外文翻译 建筑施工 外文文献 英文文献 文献翻译
建筑设计中英文对照外文翻译文献
建筑设计中英文对照外文翻译文献On the other hand, there is a significant amount ofliterature in the field of architecture design that is writtenin foreign languages. While it may not be as readily accessible for non-native speakers, there are many benefits to exploring literature in other languages. For example, architects who are fluent in multiple languages can have a broader understanding of different cultural approaches to architecture. By reading literature in foreign languages, architects can gain insights into design concepts and practices that may not be covered in English-language sources. This can lead to a more diverse and innovative approach to design.However, one challenge with accessing literature in foreign languages is the accuracy of translations. Architecture is a technical field with specific terminology, and it is important to ensure that translations accurately convey the intended meaning. In some cases, the translation of technical terms and concepts may not accurately convey their full meaning, which can lead to misunderstandings or confusion. Architects who rely on translated literature should be cautious and ensure they verify the accuracy of the translations with experts in the field.Despite these challenges, it is essential for architects to explore literature in multiple languages to stay informed and to gain a global perspective on architecture design. By consideringboth English and foreign language translated literature, architects can access a wider range of resources and insights. Additionally, architects should consider collaborating with colleagues who are fluent in different languages to ensure accurate translation and interpretation of foreign language sources.In conclusion, architecture design is a field that benefits from accessing literature in multiple languages. English provides a wealth of resources and is the global language of academia. However, architects who can access and read literature in foreign languages can gain new perspectives and insights into different cultural approaches to design. While caution should be taken to verify the accuracy of translations, architects should explore literature in multiple languages to broaden their understanding and enhance their creative problem-solving skills.。
建筑施工质量管理体系外文翻译参考文献
建筑施工质量管理体系外文翻译参考文献1. GB/T -2016 英文名称：Quality management systems--Requirements《质量管理体系要求》2. GB/T -2016 英文名称：Quality management systems--Guidelines for the application of ISO 9001:2015《质量管理体系应用指南》3. GB -2013 英文名称：Code for construction quality acceptance of building engineering《建筑工程质量验收规范》4. GB -2011 英文名称：Code for acceptance of constructional quality of masonry engineering《砌体工程施工质量验收规范》5. GB -2010 英文名称：Code for design of concrete structures《混凝土结构设计规范》6. GB -2013 英文名称：Standard for building drawing standardization《建筑施工图件编制规范》7. GB -2001 英文名称：Code for acceptance of construction quality of pile foundation engineering《桩基工程施工质量验收规范》8. /T 11-2017 英文名称：Technical specification for concrete structure of tall building《高层建筑混凝土结构技术规范》9. 63-2013 英文名称：Technical specification for strengthening of building structures using carbon fiber reinforced plastics 《建筑结构加固碳纤维布增强复合材料技术规范》10. 81-2002 英文名称：Technical specification for application of sprayed mortar in building construction and acceptance of quality 《建筑喷涂砂浆工程施工及质量验收技术规定》。
建筑外文文献及翻译(参考模板)
外文原文Study on Human Resource Allocation in Multi-Project Based on the Priority and the Cost of ProjectsLin Jingjing , Zhou GuohuaSchoolofEconomics and management, Southwest Jiao tong University ,610031 ,China Abstract----This paper put forward the a ffecting factors of project’s priority. which is introduced into a multi-objective optimization model for human resource allocation in multi-project environment . The objectives of the model were the minimum cost loss due to the delay of the time limit of the projects and the minimum delay of the project with the highest priority .Then a Genetic Algorithm to solve the model was introduced. Finally, a numerical example was used to testify the feasibility of the model and the algorithm.Index Terms—Genetic Algorithm, Human Resource Allocation, Multi-project’s project’s priority .1.INTRODUCTIONMore and more enterprises are facing the challenge of multi-project management, which has been the focus among researches on project management. In multi-project environment ,the share are competition of resources such as capital , time and human resources often occur .Therefore , it’s critical to schedule projects in order to satisfy the different resource demands and to shorten the projects’ duration time with resources constrained ,as in [1].For many enterprises ,the human resources are the most precious asset .So enterprises should reasonably and effectively allocate each resource , especially the human resource ,in order to shorten the time and cost of projects and to increase the benefits .Some literatures have discussed the resource allocation problem in multi-project environment with resources constrained. Reference [1] designed an iterative algorithm and proposeda mathematical model of the resource-constrained multi-project scheduling .Basedon work breakdown structure (WBS) and Dantzig-Wolfe decomposition method ,a feasible multi-project planning method was illustrated , as in [2] . References [3,4]discussed the resource-constrained project scheduling based on Branch Delimitation method .Reference [5] put forward the framework of human resource allocation in multi-project in Long-term ,medium-term and short-term as well as research and development(R&D) environment .Basedon GPSS language, simulation model of resources allocation was built to get the project’s duration time and resources distribution, as in [6]. Reference [7] solved the engineering project’s resources optimization problem using Genetic Algorithms. These literatures reasonably optimized resources allocation in multi-project, but all had the same prerequisite that the project’s importance is the same to each other .This paper will analyze the effects of project’s priority on human resource allocation ,which is to be introduced into a mathematical model ;finally ,a Genetic Algorithm is used to solve the model.2.EFFECTS OF PROJECTS PRIORITY ON HUMAN RESOUCE ALLOCATIONAND THE AFFECTING FACTORS OF PROJECT’S PRIORITYResource sharing is one of the main characteristics of multi-project management .The allocation of shared resources relates to the efficiency and rationality of the use of resources .When resource conflict occurs ,the resource demand of the project with highest priority should be satisfied first. Only after that, can the projects with lower priority be considered.Based on the idea of project classification management ,this paper classifies the affecting factors of project’s priority into three categories ,as the project’s benefits ,the complexity of project management and technology , and the strategic influence on the enterprise’s future development . The priority weight of the project is the function of the above three categories, as shown in (1).W=f(I,c,s…) (1)Where w refers to project’s priority weight; I refers to the benefits of th e project; c refers to the complexity of the project, including the technology and management; s refers to the influence of the project on enterprise .The bigger the values of the three categories, the higher the priority is.3.HUMAN RESOURCE ALLOCATION MODEL IN MULTI-PROJECTENVIRONMENT3.1Problem DescriptionAccording to the constraint theory, the enterprise should strictly differentiate the bottleneck resources and the non-bottleneck resources to solve the constraint problem of bottleneck resources .This paper will stress on the limited critical human resources being allocated to multi-project with definite duration times and priority.To simplify the problem, we suppose that that three exist several parallel projects and a shared resources storehouse, and the enterprise’s operation only involves one kind of critical human resources. The supply of the critical human resource is limited, which cannot be obtained by hiring or any other ways during a certain period .when resource conflict among parallel projects occurs, we may allocate the human resource to multi-project according to project’s priorities .The allocation of non-critical independent human resources is not considered in this paper, which supposes that the independent resources that each project needs can be satisfied.Engineering projects usually need massive critical skilled human resources in some critical chain ,which cannot be substituted by the other kind of human resources .When the critical chains of projects at the same time during some period, there occur resource conflict and competition .The paper also supposes that the corresponding network planning of various projects have already been established ,and the peaks of each project’s resources demand have been optimized .The delay of the critical chain will affect the whole project’s duration time .3.2 Model HypothesesThe following hypotheses help us to establish a mathematical model:(1)The number of mutually independent projects involved in resourceallocation problem in multi-project is N. Each project is indicated withQ i,while i=1,2, … N.(2)The priority weights of multi-project have been determined ,which arerespectively w1,w 2…w n .(3) The total number of the critical human resources is R ,with r k standingfor each person ,while k=1,2, …,R(4) Δk i = ⎩⎨⎧others toprojectQ rcer humanresou i k 01(5) Resources capturing by several projects begins on time. t E i is theexpected duration time of project I that needs the critical resources tofinish some task after time t ,on the premise that the human resourcesdemand can be satisfied .tAi is the real duration time of project I thatneeds the critical resource to finish some task after time t .(6) According to the contract ,if the delay of the project happens the dailycost loss due to the delay is △c i for pro ject I .According to the project’simportance ,the delay of a project will not only cause the cost loss ,butwill also damage the prestige and status of the enterprise .(while thelatent cost is difficult to quantify ,it isn’t considered in this articletemporarily.)(7) From the hypothesis (5) ,we can know that after time t ,the time-gapbetween the real and expected duration time of project I that needs thecritical resources to finish some task is △t i ,( △t i =t A i -t E i ). For thereexists resources competition, the time –gap is necessarily a positivenumber.(8) According to hypotheses (6) and (7), the total cost loss of project I is C i(C i = △t i * △C i ).(9) The duration time of activities can be expressed by the workload ofactivities divided by the quantity of resources ,which can be indicatedwith following expression of t A i =ηi / R i * ,.In the expression , ηi refersto the workload of projects I during some period ,which is supposed tobe fixed and pre-determined by the project managers on project planningphase ; R i * refers to the number of the critical human resources beingallocated to projects I actually, with the equation Ri * =∑=Rk ki 1δ existing. Due to the resource competition the resourcedemands of projects with higherPriorities may be guarantee, while those projects with lower prioritiesmay not be fully guaranteed. In this situation, the decrease of theresource supply will lead to the increase of the duration time of activitiesand the project, while the workload is fixed.3.3 Optimization ModelBased on the above hypotheses, the resource allocation model inmulti-project environment can be established .Here, the optimizationmodel is :F i =min Z i = min∑∑==Ni i N i Ci 11ω =min i i Ni i N i c t ∆∆∑∑==11ω (2) =min ∑∑==N i i N i 11ω )E i R i ki i t - ⎝⎛∑=1δη i c ∆ 2F =min Z 2=min ()i t ∆=min )E i R i ki i t -⎝⎛∑=1δη (3) Where wj=max(wi) ,(N j i 3,2,1,=∀) (4)Subject to : 0∑∑==≤R k ki N i 11δ=R (5)The model is a multi-objective one .The two objective functions arerespectively to minimize the total cost loss ,which is to conform to theeconomic target ,and to shorten the time delay of the project with highestpriority .The first objective function can only optimize the apparenteconomic cost ;therefore the second objective function will help to makeup this limitation .For the project with highest priority ,time delay will damage not only the economic benefits ,but also the strategy and the prestige of the enterprise .Therefore we should guarantee that the most important project be finished on time or ahead of schedule .4.SOLUTION TO THE MULTI-OBJECTIVE MODEL USING GENETICALGORITHM4.1The multi-objective optimization problem is quite common .Generally ,eachobjective should be optimized in order to get the comprehensive objective optimized .Therefore the weight of each sub-objective should be considered .Reference [8] proposed an improved ant colony algorithm to solve this problem .Supposed that the weights of the two optimizing objectives are αand β ,where α+β=1 .Then the comprehensive goal is F* ,where F*=αF1+βF2.4.2The Principle of Genetic AlgorithmGenetic Algorithm roots from the concepts of natural selection and genetics .It’s a random search technique for global optimization in a complex search space .Because of the parallel nature and less restrictions ,it has the key features of great currency ,fast convergence and easy calculation .Meanwhile ,its search scope is not limited ,so it’s an effective method to solve the resource balancing problem ,as in [9].The main steps of GA in this paper are as follow:(1)EncodingAn integer string is short, direct and efficient .According to thecharacteristics of the model, the human resource can be assigned to be acode object .The string length equals to the total number of humanresources allocated.(2)Choosing the fitness functionThis paper choose the objective function as the foundation of fitnessfunction .To rate the values of the objective function ,the fitness of then-th individual is 1/n。
建筑施工质量控制技术外文翻译参考文献
建筑施工质量控制技术外文翻译参考文献1. Zhang, H., Yu, S., & Yang, C. (2019). Research on Quality Control Technology of Construction Engineering. Journal of Wuhan University of Technology. 41(9), 28-33.2. Li, J., & Wang, Y. (2018). Application of Quality Management Technology in Construction Projects. China Construction Science and Technology. 45(2), 60-64.3. Chen, X., & Li, Z. (2017). Quality Improvement Measures and Evaluation Index System for Construction Projects. Construction Engineering Technology and Design. 28(4), 65-70.4. Zhao, Y., & Liu, W. (2016). Study on Quality Control Technology of Construction Engineering based on BIM. Modern Construction Technology. 57(1), 38-42.5. Wang, L., & Zhang, Y. (2015). Application of Lean Construction in Quality Control of Construction Projects. Construction Technology and Economy. 36(6), 45-49.6. Wu, Q., & Xu, H. (2014). Research on Quality Control Technology Innovation of Construction Projects. Journal of Building Materials and Structures. 35(8), 51-55.7. Li, H., & Zhu, L. (2013). Application of Six Sigma in Quality Control of Construction Engineering. China Construction Economy.40(3), 70-75.8. Tang, J., & Guan, J. (2012). Analysis of Quality Control Measures in Construction Engineering. Construction Engineering and Technology. 33(5), 32-37.9. Zhang, G., & Zhang, Q. (2011). Study on Quality Control of Construction Engineering based on PDCA Cycle. Construction Science and Management. 51(9), 47-51.10. Liu, Y., & Wang, X. (2010). Key Points and Methods for Quality Control of Construction Engineering. Building Construction. 42(4), 34-38.。
建筑英文文献及翻译
建筑英文文献及翻译第一篇：建筑英文文献及翻译外文原文出处: NATO Science for Peace and Security Series C: Environmental Security, 2009, Increasing Seismic Safety by Combining Engineering Technologies and Seismological Data, Pages 147-149动力性能对建筑物的破坏引言：建筑物在地震的作用下，和一些薄弱的建筑结构中，动力学性能扮演了一个很重要的角色。
特别是要满足最基本的震动周期，无论是在设计的新建筑，或者是评估已经有的建筑，使他们可以了解地震的影响。
许多标准(例如：欧标，2003；欧标，2006)，建议用简单的表达式来表达一个建筑物的高度和他的基本周期。
这样的表达式被牢记在心，得出标定设计(高尔和乔谱拉人，1997)，从而人为的低估了标准周期。
因为这个原因，他们通常提供比较低的设计标准当与那些把设计基础标准牢记在心的人(例：乔普拉本和高尔，2000)。
当后者从已进行仔细建立的数字模型中得到数值(例：克劳利普和皮诺，2004；普里斯特利权威，2007)。
当数字估计与周围震动测量的实验结果相比较，有大的差异，提供非常低的周期标准(例：纳瓦洛苏达权威，2004)。
一个概述不同的方式比较确切的结果刊登在马西和马里奥(2008)；另外，一个高级的表达式来指定更有说服力的坚固建筑类型，提出了更加准确的结构参数表(建筑高度，开裂，空隙填实，等等)。
联系基础和上层建筑的震动周期可能发生共振的效果。
这个原因对于他们的振动，可能建筑物和土地在非线性运动下受到到破坏，这个必须被重视。
通常，结构工程师和岩土工程师有不同的观点在共振作用和一些变化的地震活动。
结构工程师们认为尽管建筑物和土壤的自振周期和地震周期都非常的接近。
但对于建筑物周期而言，到底是因为结构还是非结构造成的破坏提出了疑问。
建筑施工中英文对照外文翻译文献
建筑施工中英文对照外文翻译文献建筑施工中英文对照外文翻译文献(文档含英文原文和中文翻译)外文：Building construction concrete crack ofprevention and processingAbstractThe crack problem of concrete is a widespread existence but again difficult in solve of engineering actual problem, this text carried on a study analysis to a little bit familiar crack problem in the concrete engineering, and aim at concrete the circumstance put forward some prevention, processing measure.Keyword:Concrete crack prevention processingForewordConcrete's ising 1 kind is anticipate by the freestone bone, cement, water and other mixture but formation of the in addition material of quality brittleness not and all material.Because the concrete construction transform with oneself, control etc. a series problem, harden model of in the concrete existence numerous tiny hole, spirit cave and tiny crack, is exactly because these beginning start blemish of existence just make the concrete present one some not and all the characteristic of quality.The tiny crack is a kind of harmless crack and accept concrete heavy, defend Shen and a little bit other use function not a creation to endanger.But after the concrete be subjected to lotus carry, difference in temperature etc. function, tiny crack would continuously of expand with connect, end formation we can see without the aid of instruments of macro view the crack be also the crack that the concrete often say in the engineering.Concrete building and Gou piece usually all take sewer to make of, because of crack of existence and development usually make inner part of reinforcing bar etc. material creation decay, lower reinforced concrete material of loading ability, durable and anti- Shen ability, influence building of external appearance, service life, severity will threat arrive people's life and property safety.A lot of all of crash of engineerings is because of the unsteady development of the crack with the result that.Modern age scienceresearch with a great deal of of the concrete engineering practice certificate, in the concrete engineering crack problem is ineluctable, also acceptable in certainly of the scope just need to adopt valid of measure will it endanger degree control at certain of scope inside.The reinforced concrete norm is also explicit provision:Some structure at place of dissimilarity under the condition allow existence certain the crack of width.But at under construction should as far as possible adopt a valid measure control crack creation, make the structure don't appear crack possibly or as far as possible decrease crack of amount and width, particularly want to as far as possible avoid harmful crack of emergence, insure engineering quality thus.Concrete crack creation of the reason be a lot of and have already transformed to cause of crack:Such as temperature variety, constringency, inflation, the asymmetry sink to sink etc. reason cause of crack;Have outside carry the crack that the function cause;Protected environment not appropriate the crack etc. caused with chemical effect.Want differentiation to treat in the actual engineering, work°out a problem according to the actual circumstance.In the concrete engineering the familiar crack and the prevention1.Stem Suo crack and preventionStem the Suo crack much appear after the concrete protect be over of a period of time or concrete sprinkle to build to complete behind of around a week.In the cement syrup humidity of evaporate would creation stem Suo, and this kind of constringency is can't negative.Stem Suo crack of the creation be main is because of concrete inside outside humidity evaporate degree dissimilarity but cause to transform dissimilarity of result:The concrete is subjected to exterior condition of influence, surface humidity loss lead quick, transform bigger, inner part degree of humidity variety smaller transform smaller, bigger surface stem the Suo transform to be subjected to concrete inner part control, creation more big pull should dint but creation crack.The relative humidity is more low, cement syrup body stem Suo more big, stem the Suo crack be more easy creation.Stem the Suo crack is much surface parallel lines form or the net shallow thin crack, width many between 0.05-0.2 mm, the flat surface part much see in the big physical volume concrete and follow it more in thinner beam plank short todistribute.Stem Suo crack usually the anti- Shen of influence concrete, cause the durable of the rust eclipse influence concrete of reinforcing bar, under the function of the water pressure dint would creation the water power split crack influence concrete of loading dint etc..Concrete stem the Suo be main with water ash of the concrete ratio, the dosage of the composition, cement of cement, gather to anticipate of the dosage of the property and dosage, in addition etc. relevant.Main prevention measure:While being to choose to use the constringency quantity smaller cement, general low hot water mire and powder ash from stove cement in the adoption, lower the dosage of cement.Two is a concrete of stem the Suo be subjected to water ash ratio of influence more big, water ash ratio more big, stem Suo more big, so in the concrete match the ratio the design should as far as possible control good water ash ratio of choose to use, the Chan add in the meantime accommodation of reduce water.Three is strict control concrete mix blend with under construction of match ratio, use of concrete water quantity absolute can't big in match ratio design give settle of use water quantity.Four is the earlier period which strengthen concrete to protect, and appropriate extension protect of concrete time.Winter construction want to be appropriate extension concrete heat preservation to overlay time, and Tu2 Shua protect to protect.Five is a constitution the accommodation is in the concrete structure of the constringency sew.2.The Su constringency crack and preventionSu constringency is the concrete is before condense, surface because of lose water quicker but creation of constringency.The Su constringency crack is general at dry heat or strong wind the weather appear, crack's much presenting in the center breadth, both ends be in the centerthin and the length be different, with each other not coherent appearance.Shorter crack general long 20-30 cm, the longer crack can reach to a 2-3 m, breadth 1-5 mm.It creation of main reason is:The concrete is eventually almost having no strength or strength before the Ning very small, perhaps concrete just eventually Ning but strength very hour, be subjected to heat or compare strong wind dint of influence, the concrete surface lose water to lead quick, result in in the capillary creation bigger negative press but make a concrete physical volume sharplyconstringency, but at this time the strength of concrete again can't resist its constringency, therefore creation cracked.The influence concrete Su constringency open the main factor of crack to have water ash ratio, concrete of condense time, environment temperature, wind velocity, relative humidity...etc..Main prevention measure:One is choose to use stem the Suo value smaller higher Huo sour salt of the earlier period strength or common the Huo sour brine mire.Two is strict the control water ash ratio, the Chan add to efficiently reduce water to increment the collapse of concrete fall a degree and with easy, decrease cement and water of dosage.Three is to sprinkle before building concrete, water basic level and template even to soak through.Four is in time to overlay the perhaps damp grass mat of the plastics thin film, hemp slice etc., keep concrete eventually before the Ning surface is moist, perhaps spray to protect etc. to carry on protect in the concrete surface.Five is in the heat and strong wind the weather to want to establish to hide sun and block breeze facilities, protect in time.3.Sink to sink crack and preventionThe creation which sink to sink crack is because of the structure foundation soil quality not and evenly, loose soft or return to fill soil dishonest or soak in water but result in the asymmetry sink to decline with the result that;Perhaps because of template just degree shortage, the template propped up to once be apart from big or prop up bottom loose move etc. to cause, especially at winter, the template prop up at jelly soil up, jelly the soil turn jelly empress creation asymmetry to sink to decline and cause concrete structure creation crack.This kind crack many is deep enter or pierce through sex crack, it alignment have something to do with sinking to sink a circumstance, general follow with ground perpendicular or present 30 °s-45 °Cape direction development, bigger sink to sink crack, usually have certain of wrong, crack width usually with sink to decline quantity direct proportion relation.Crack width under the influence of temperature variety smaller.The foundation after transform stability sink to sink crack also basic tend in stability.Main prevention measure:One is rightness loose soft soil, return to fill soil foundation a construction at the upper part structure front should carry on necessity ofHang solid with reinforce.Two is the strength that assurance template is enough and just degree, and prop up firm, and make the foundation be subjected to dint even.Three is keep concrete from sprinkle infusing the foundation in the process is soak by water.Four is time that template tore down to can't be too early, and want to notice to dismantle a mold order of sequence.Five is at jelly soil top take to establish template to notice to adopt certain of prevention measure.4.Temperature crack and preventionTemperature crack much the occurrence is in big surface or difference in temperature variety of the physical volume concrete compare the earth area of the concrete structure.Concrete after sprinkling to build, in the hardening the process, cement water turn a creation a great deal of of water turn hot, .(be the cement dosage is in the 350-550 kg/m 3, each sign square the rice concrete will release a calories of 17500-27500 kJ and make concrete internal thus the temperature rise to reach to 70 ℃or so even higher)Because the physical volume of concrete be more big, a great deal of of water turn hot accumulate at the concrete inner part but not easy send forth, cause inner part the temperature hoick, but the concrete surface spread hot more quick, so formation inside outside of bigger difference in temperature, the bigger difference in temperature result in inner part and exterior hot the degree of the bulge cold Suo dissimilarity, make concrete surface creation certain of pull should dint.When pull should dint exceed the anti- of concrete pull strength extreme limit, concrete surface meeting creation crack, this kind of crack much occurrence after the concrete under construction period.In the concrete of under construction be difference in temperature variety more big, perhaps is a concrete to be subjected to assault of cold wave etc., will cause concrete surface the temperature sharply descend, but creation constringency, surface constringency of the concrete be subjected to inner part concrete of control, creation very big of pull should dint but creation crack, this kind of crack usually just in more shallow scope of the concrete surface creation.The alignment of the temperature crack usually none settle regulation, big area structure the crack often maneuver interleave;The size bigger structure of the beam plank length, the crack run parallel with short side more;Thorough with pierce throughsex of temperature crack general and short side direction parallelism or close parallelism, crack along long side cent the segment appear, in the center more airtight.Crack width the size be different, be subjected to temperature variety influence more obvious, winter compare breadth, summer more narrow.The concrete temperature crack that the heat inflation cause is usually in the center the thick both ends be thin, but cold Suo crack of thick thin variety not too obvious.The emergence of the this kind crack will cause the rust eclipse of reinforcing bar, the carbonization of concrete, the anti- jelly which lower concrete melt, anti- tired and anti- Shen ability etc..Main prevention measure:One is as far as possible choose to use low hot or medium hot water mire, like mineral residue cement, powder ash from stove cement...etc..Two is a decrease cement dosage, cement dosage as far as possible the control is in the 450 kg/m 3 following.Three is to lower water ash ratio, water ash of the general concrete ratio control below 0.6.Four is improvement the bone anticipate class to go together with, the Chan add powder ash from stove or efficiently reduce water etc. to come to reduce cement dosage and lower water to turn hot.Five is an improvement concrete of mix blend to process a craft, lower sprinkle of concrete to build temperature.Six is the in addition that the Chan add a have of fixed amount to reduce water and increase Su, slow Ning etc. function in the concrete, improvement the concrete mix to match a thing of mobility, protect water, lower water to turn hot, postpone hot Feng of emergence time.Seven is the heat season sprinkle to build can the adoption take to establish to hide sun plank etc. assistance measure control concrete of Wen Sheng, lower to sprinkle temperature of build the concrete.Eight is the temperature of big physical volume concrete should the dint relate to structure size, concrete structure size more big, temperature should dint more big, so want reasonable arrangement construction work preface, layering, cent the piece sprinkle to build, for the convenience of in spread hot, let up control.Nine is at great inner part constitution of the physical volume concrete cool off piping, cold water perhaps cold air cool off, let up concrete of inside outside difference in temperature.Ten is the supervision which strengthen concrete temperature, adopt to cool off in time, protection measure.11 is to reserve temperature constringency to sew.12 is to let up to control, sprinkle proper before building concrete in the Ji rockand old concrete top build a 5 mm or so sand mat a layer or usage asphalt etc. material Tu2 Shua.13 is to strengthen concrete to protect, the concrete after sprinkle build use moist grass Lian in time, hemp slice's etc. overlay, and attention sprinkle water to protect, appropriate extension protect time, assurance the concrete surface be slow-moving cool off.At the cold season, concrete surface should constitution heat preservation measure, in order to prevent cold wave assault.14 is the allocation be a little amount in the concrete of reinforcing bar perhaps add fiber material concrete of temperature crack control at certain of scope inside.5.Crack and prevention that the chemical reaction causeAlkali bone's anticipating the crack that reaction crack and reinforcing bar rust eclipse cause is the most familiar in the reinforced concrete structure of because of chemical reaction but cause of crack.The concrete blend a future reunion creation some alkalescence ion, these ion with some activity the bone anticipate creation chemical reaction and absorb surroundings environment in of water but the physical volume enlarge, make concrete crisp loose, inflation open crack.In this kind of crack general emergence concrete structure usage period, once appear very difficult remediable, so should at under construction adopt valid the measure carry on prevention.Main of prevention measure:While being to choose to anticipate with the alkali activity small freestone bone.Two is the in addition which choose to use low lye mire with low alkali or have no alkali.Three is the Chan which choose to use accommodation with anticipate to repress an alkali bone to anticipate reaction.Because the concrete sprinkle to build, flap Dao bad perhaps is a reinforcing bar protection layer thinner, the harmful material get into concrete to make reinforcing bar creation rust eclipse, the reinforcing bar physical volume of the rust eclipse inflation, cause concrete bulge crack, the crack of this kind type much is a crack lengthways, follow the position of reinforcing bar ually of prevent measure from have:One is assurance reinforcing bar protection the thickness of the layer.Two is a concrete class to go together with to want good.Three is a concrete to sprinkle to note and flap Dao airtight solid.Four is a reinforcing bar surface layer Tu2 Shua antisepsiscoating.Crack processingThe emergence of the crack not only would influence structure of whole with just degree, return will cause the rust eclipse of reinforcing bar, acceleration concrete of carbonization, lower durable and anti- of concrete tired, anti- Shen ability.Therefore according to the property of crack and concrete circumstance we want differentiation to treat, in time processing, with assurance building of safety usage.The repair measure of the concrete crack is main to have the following some method:Surface repair method, infuse syrup, the Qian sew method, the structure reinforce a method, concrete displacement method, electricity chemistry protection method and imitate to living from heal method.Surface repair the method be a kind of simple, familiar of repair method, it main be applicable to stability and to structure loading the ability don't have the surface crack of influence and deep enter crack of processing.The processing measure that is usually is a surface in crack daubery cement syrup, the wreath oxygen gum mire or at concrete surface Tu2 Shua paint, asphalt etc. antisepsis material, at protection of in the meantime for keeping concrete from continue under the influence of various function to open crack, usually can adoption the surface in crack glue to stick glass fiber cloth etc. measure.1, infuse syrup, the Qian sew methodInfuse a syrup method main the concrete crack been applicable to have influence or have already defend Shen request to the structure whole of repair, it is make use of pressure equipments gum knot the material press into the crack of concrete, gum knot the material harden behind and concrete formation one be whole, thus reinforce of purpose.The in common use gum knot material has the cement the syrup, epoxy, A Ji C Xi sour ester and gather ammonia ester to equalize to learn material.The Qian sew a method is that the crack be a kind of most in common use method in, it usually is follow the crack dig slot, the Qian fill Su in the slot or rigid water material with attain closing crack of purpose.The in common use Su material has PVC gum mire,plastics ointment, the D Ji rubber etc.;In common use rigid water material is the polymer cement sand syrup.2, the structure reinforce a methodWhen the crack influence arrive concrete structure of function, will consideration adopt to reinforce a method to carry on processing to the concrete structure.The structure reinforce medium in common use main have the following a few method:The piece of enlargement concrete structure in every aspect accumulate, outside the Cape department of the Gou piece pack type steel, adoption prepare should the dint method reinforce, glue to stick steel plate to reinforce, increase to establish fulcrum to reinforce and jet the concrete compensation reinforce.3, concrete displacement methodConcrete displacement method is processing severity damage concrete of a kind of valid method, this method be first will damage of the concrete pick and get rid of, then again displacement go into new of concrete or other material.The in common use displacement material have:Common concrete or the cement sand syrup, polymer or change sex polymer concrete or sand syrup.4, the electricity chemistry protection methodThe electricity chemistry antisepsis is to make use of infliction electric field in lie the quality of electricity chemical effect, change concrete or reinforced concrete the environment appearance of the place, the bluntness turn reinforcing bar to attain the purpose of antisepsis.Cathode protection method, chlorine salt's withdrawing a method, alkalescence to recover a method is a chemistry protection method in three kinds of in common use but valid method.The advantage of this kind of method is a protection method under the influence of environment factor smaller, apply reinforcing bar, concrete of long-term antisepsis, since can used for crack structure already can also used for new set up structure.5, imitate to living from legal moreImitate to living from heal the method be a kind of new crack treatment, its mimicry living creature organization secrete a certain material towards suffering wound part auto, but make the wound part heal of function, join some and special composition(suchas contain to glue knot of the liquid Xin fiber or capsule) in the concrete of the tradition the composition, at concrete inner part formation the intelligence type imitate to living from heal nerve network system, be the concrete appear crack secrete a parts of liquid Xin fiber can make the crack re- heal.ConclusionThe crack is widespread in the concrete structure existence of a kind of phenomenon, it of emergence not only will lower the anti- Shen of building ability, influence building of usage function, and will cause the rust eclipse of reinforcing bar, the carbonization of concrete, lower the durable of material, influence building of loading ability, so want to carry on to the concrete crack earnest research, differentiation treat, adoption reasonable of the method carry on processing, and at under construction adopt various valid of prevention measure to prevention crack of emergence and development, assurance building and Gou piece safety, stability work.From《CANADIAN JOURNAL OF CIVIL ENGINEERING》译文：建筑施工混凝土裂缝的预防与处理混凝土的裂缝问题是一个普遍存在而又难于解决的工程实际问题，本文对混凝土工程中常见的一些裂缝问题进行了探讨分析，并针对具体情况提出了一些预防、处理措施。
外文文献译文(建筑工程)
黄山学院毕 业 设 计系 别：_________________________班 级：_________________________姓 名：_________________________指 导 教 师：_______郭富__________________2010年5月8 日刘星 10土对本（2）班 土木工程系目录1 中文翻译 (1)1.1钢筋混凝土 (1)1.2土方工程 (2)1.3结构的安全度 (3)2 外文翻译 (6)2.1 Reinforced Concrete (6)2.2 Earthwork (7)2.3 Safety of Structures (9)1 中文翻译1.1钢筋混凝土素混凝土是由水泥、水、细骨料、粗骨料（碎石或；卵石）、空气，通常还有其他外加剂等经过凝固硬化而成。
将可塑的混凝土拌合物注入到模板内，并将其捣实，然后进行养护，以加速水泥与水的水化反应，最后获得硬化的混凝土。
其最终制成品具有较高的抗压强度和较低的抗拉强度。
其抗拉强度约为抗压强度的十分之一。
因此，截面的受拉区必须配置抗拉钢筋和抗剪钢筋以增加钢筋混凝土构件中较弱的受拉区的强度。
由于钢筋混凝土截面在均质性上与标准的木材或钢的截面存在着差异，因此，需要对结构设计的基本原理进行修改。
将钢筋混凝土这种非均质截面的两种组成部分按一定比例适当布置，可以最好的利用这两种材料。
这一要求是可以达到的。
因混凝土由配料搅拌成湿拌合物，经过振捣并凝固硬化，可以做成任何一种需要的形状。
如果拌制混凝土的各种材料配合比恰当，则混凝土制成品的强度较高，经久耐用，配置钢筋后，可以作为任何结构体系的主要构件。
浇筑混凝土所需要的技术取决于即将浇筑的构件类型，诸如：柱、梁、墙、板、基础，大体积混凝土水坝或者继续延长已浇筑完毕并且已经凝固的混凝土等。
对于梁、柱、墙等构件，当模板清理干净后应该在其上涂油，钢筋表面的锈及其他有害物质也应该被清除干净。
建筑类外文文献及中文翻译资料讲解
forced concrete structure reinforced with anoverviewReinSince the reform and opening up, with the national economy's rapid and sustained development of a reinforced concrete structure built, reinforced with the development of technology has been great. Therefore, to promote the use of advanced technology reinforced connecting to improve project quality and speed up the pace of construction, improve labor productivity, reduce costs, and is of great significance.Reinforced steel bars connecting technologies can be divided into two broad categories linking welding machinery and steel. There are six types of welding steel welding methods, and some apply to the prefabricated plant, and some apply to the construction site, some of both apply. There are three types of machinery commonly used reinforcement linking method primarily applicable to the construction site. Ways has its own characteristics and different application, and in the continuous development and improvement. In actual production, should be based on specific conditions of work, working environment and technical requirements, the choice of suitable methods to achieve the best overall efficiency.1、steel mechanical link1.1 radial squeeze linkWill be a steel sleeve in two sets to the highly-reinforced Department with superhigh pressure hydraulic equipment (squeeze tongs) along steel sleeve radial squeeze steel casing, in squeezing out tongs squeeze pressure role of a steel sleeve plasticity deformation closely integrated with reinforced through reinforced steel sleeve and Wang Liang's Position will be two solid steel bars linkedCharacteristic: Connect intensity to be high, performance reliable, can bear high stress draw and pigeonhole the load and tired load repeatedly.Easy and simple to handle, construction fast, save energy and material, comprehensive economy profitable, this method has been already a large amount of application in the project.Applicable scope : Suitable for Ⅱ, Ⅲ, Ⅳgrade reinforcing bar (including welding bad reinfor cing bar ) with ribbing of Ф 18- 50mm, connection between the same diameter or different diameters reinforcing bar .1.2must squeeze linkExtruders used in the covers, reinforced axis along the cold metal sleeve squeeze dedicated to insert sleeve Lane two hot rolling steel drums into a highly integrated mechanical linking methods.Characteristic: Easy to operate and joining fast and not having flame homework , can construct for 24 hours , save a large number of reinforcing bars and energy. Applicable scope : Suitable for , set up according to first and second class antidetonation requirement -proof armored concrete structure ФⅡ, Ⅲgrade reinforcing bar with ribbing of hot rolling of 20- 32mm join and construct live.1.3 cone thread connectingUsing cone thread to bear pulled, pressed both effort and self-locking nature, undergo good principles will be reinforced by linking into cone-processing thread at the moment the value of integration into the joints connecting steel bars.Characteristic: Simple , all right preparatory cut of the craft , connecting fast, concentricity is good, have pattern person who restrain from advantage reinforcing bar carbon content.Applicable scope : Suitable for the concrete structure of the industry , civil buil ding and general structures, reinforcing bar diameter is for Фfor the the 16- 40mm one Ⅱ, Ⅲgrade verticality, it is the oblique to or reinforcing bars horizontal join construct live.conclusionsThese are now commonly used to connect steel synthesis methods, which links technology in the United States, Britain, Japan and other countries are widely used. There are different ways to connect their different characteristics and scope of theactual construction of production depending on the specific project choose a suitable method of connecting to achieve both energy conservation and saving time limit for a project ends.钢筋混凝土结构中钢筋连接综述改革开放以来，随着国民经济的快速、持久发展，各种钢筋混凝土建筑结构大量建造，钢筋连接技术得到很大的发展。
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反思前瞻规划优化施工流程Farook Hamzeh Glenn Ballard Iris D. Tommelein摘要研究的问题：如何改善前瞻规划在建设行业的做法来提高生产计划的可靠性？目的：为了评估前瞻规划的性能，寻找一个标准化的做法，使前瞻规划与活动执行有紧密的联系，来提高生产计划的可靠性。
研究设计/方法：本研究采用案例分析，行业访谈，和行业调查，以评估目前在北美、南美和欧洲的建设项目执行的前瞻规划。
研究结果：研究结果显示存在与去年规划系统规则的不符合，前瞻规划与标准化做法的不足，识别和清除限制的迟缓，而且没有对计划失败的分析。
关键词：前瞻规划，生产计划，生产控制，精益建设，最后的规划系统，规划建设。
简介建筑、工程与施工是受变化问题的困扰的，即破坏项目绩效和扰乱施工流程导致对项目时间、成本和质量造成的不利影响（Hamzeh等，2007年，霍普和Spearman2008年，萨利姆等。
2006年，克莱顿1966年）。
组织使用许多种不同的方法来维持生产流程的一致性和屏蔽产量内部业务流程以及外部环境的变化。
汤普森（1967）着重介绍了这些方法，其中包括：•预测•缓冲•平滑各种预测方法是用于预测在内部流程和生产原料中的变化。
然而，预测不能满足所有的变化，并且有许多限制：越详细的预测越不准确，越遥远的预测越容易出错。
（纳米亚斯2009年）。
缓冲用于减轻同时在输入侧和输出侧的工艺变化。
输入通常需要成功执行的任务包括：信息，先决条件工作，人力资源，空间，材料，设备，外部条件和资金（巴拉德＆Howell公司1994年，科斯基拉2000年）。
缓冲区可以采取的三种主要形式：时间，库存和产能。
时间缓冲是分配松弛的活动，利用额外的库存缓冲库存以应对供应的变化，以及用容量缓存，保留额外的容量，如加班或只在需要的时候维持机器工作，以适应激增的负荷。
平滑的供应和需求的变化是另一种方法，组织申请由于缓冲可能的不足，以满足所有的变化，是昂贵的，并可能导致满荷。
平滑需求的一个例子在丰田生产系统中平稳的工作负荷或平准化的倡导（莱克2004年）。
虽然变化破坏了项目的绩效，生产系统可以通过设计减少这种变化，并且可以通过上述提到的方法的组合来管理这种残差。
一个生产系统可以被定义为人员和资源的集合。
（例如，机械，设备，信息），被安排设计和制造产品（“货物”或“服务”）的价值给客户（Ballard等人，2007年）。
一个生产系统的基石是生产管理，例如最近的一个规划系统已成功实施建设项目（2004年巴拉德和Howell），以提高规划的可靠性，提高生产性能，在设计和施工作业中创建可以预测的工作流程。
在任何项目中，规划过程中可能遇到各种问题的困扰。
规划涉及到的越远的项目可能越不准确（纳米亚斯2009）。
当规划师把计划推向前线专家而不涉及他们的计划发展时是很难执行的工作日程。
在一厢情愿的想法的基础上开发的短期工作计划，贸易专家没有可靠的承诺，这种短期计划就会变得更短。
如果计划失败的原因并不在识别和处理不及时，进一步的失败是必然要发生的（哈姆泽2009年）。
此外，可靠的规划依赖于有效的约束分析与排除。
约束是一个活动启动前必须存在的先决条件（例如，以前的工作，信息，劳动力，材料，设备，工具，空间，天气等）。
管理约束条件可以通过识别资源冲突和提前解决这些问题帮助优化工作计划使工作开始。
如果没有约束，是难以管理和减少工作流程不确定性的，这往往导致过程的变化（蔡等，2003）。
考虑到上述挑战，最后规划系统主张项目规划中的以下步骤：•计划越详细情，执行工作越细致（科恩，2006年）•制定工作计划要执行工作的人制定工作计划•提前识别和消除工作的限制，作为一个团队，做好工作准备，提高工作计划的可靠性•在与项目参与方协调和积极谈判的基础上，做出可靠的承诺和工作执行•从失败的计划中学习经验，找出错误的根源，并采取预防措施（巴拉德，等。
2009年）尽管该系统的优点（阿拉尔孔和克鲁兹1997年，冈萨雷斯等人，2008），在许多建设项目目前的做法显示了执行不力前瞻规划，在较大差距长期规划（主阶段附表）和短期规划（承诺/每周的工作计划），降低了可靠性规划系统，并能够建立先见之明。
本文提出了一种前瞻规划实施的一种评估，为最新规划系统的一个过程，其重点介绍了统营规划系统一些不足之处，强调的前瞻规划每周工作规划成功的一个主要驱动力的作用，并建议进行前瞻规划的指导方针有关的活动故障，操作设计，及制约因素分析。
最新的规划系统最新规划系统开发者是格伦·巴拉德和格雷格·豪威尔，其是一生产计划和控制建设工作的系统，以协助平滑的变化流，发展规划先见之明，并减少施工作业中的不确定性。
系统最初是每周的工作计划水平，但很快就把处理工作流程中的变化扩大到覆盖整个计划和进度开发过程中，从主调度，通过前瞻规划，逐步调度达到每周工作规划中。
计划完成百分比（PPC）是一个度量，用于跟踪每周的工作计划水平的性能可靠性，通过测量相对于那些计划完成任务的百分比。
因此，它有助于评估的可靠性工作计划，并开始准备工作，以执行工作计划。
PPC并不是直接衡量项目的进展，而是承诺保持在何种程度上的措施，因此在何种程度上未来的工作负载可能是可预测的。
以前的研究发现PPC和劳动生产率之间的相关性（2008年刘和巴拉德）。
PPC上提高可能产生的二次冲击工作安全和质量需要进一步的研究（1998年，巴拉德和Howell Ballard等。
2007）。
有研究表明，尽管在LPS的优势，许多企业实施系统时都面临重大障碍。
（Ballard 等人，2007;哈姆泽，2009年维亚纳等）。
为建设项目的最新规划系统的成功实施提出了一个框架。
然而，当整个规划系统（主生产计划，阶段调度，前瞻的规划，每周工作规划）执行和更新设计，PPC 项目进展情况的指标，PPC和进步应随对方。
这可以表示为如权利要求一个复杂的假设，即：H1：如果前瞻任务是从一个阶段计划结构实现到项目的结束日期和中间里程碑，如果前瞻规划是准备应该怎样做，如果每周选择什么，可以做什么工作计划由应该做在临界的顺序没有游戏的系统，PPC将随项目的进展情况而不同。
如果我们接受这个假设，那么，如果不随PPC项目的进展情况，在虚拟链的某个地方就有一个破碎的链接。
图1显示了活动打破阶段的规划系统（砾石）的过程（岩石），然后在四个规划过程中的操作（卵石）不同的按时间跨度：主生产计划，阶段调度，前瞻规划和每周工作规划。
主生产计划是一个前端的规划过程中产生的时间表描述工作在进行整个项目的持续时间。
它涉及到项目级活动，并确定重要的里程碑日期主要集中在有关合同文件和拥有者的价值主张（Tommelein和Ballard，1997）。
相调度产生的时间表，覆盖项目的每个阶段，如地基，结构框架，或完成。
在协作规划设置项目团队：（1）定义项目阶段或里程碑，（2）将其分解成组成活动，（3）时间表向后的里程碑。
合并后从不同的项目方输入和在重要的阶段识别专家和团队执行之间逆相调度的平衡，从重要的阶段里程碑（哈姆泽2009年，巴拉德和豪威尔2004）。
前瞻规划是在生产控制（执行时间表）的第一步，通常包括一个为期6周的时间。
前瞻时段随正在执行的工作类型和上下文的不同而不同。
（例如，因为这种现象的出现，在概念设计，任务可以不在详细的预见水平很远的水平。
在工厂停工时，前瞻期延伸到年底关机。
在这项研究中，重点是正常的建设项目，并在这些4至6周的时间框架是常用的前瞻规划）。
在此阶段，活动被分解成水平的生产过程/操作，约束被识别，操作的设计，和准备作业就绪（巴拉德1997年，哈姆泽2009年）。
每周工作规划（WWP）也被称为承诺计划是最系统的详细计划，展现了工作的各专业组织之间的相互依存，和直接驱动的生产过程。
计划在这个级别的可靠性促进了质量分配和可靠的承诺，使生产单元从上游业务中的不确定性被屏蔽。
这个工作任务是一个详细的测量完成可的计划。
每个计划期结束时，作业被评论，评估它们是否是完整的，从测量规划中的可靠性。
对于不完整的任务，对计划失败的原因进行分析，并采取行动，这些原因是学习和持续改进的基础（巴拉德2000年）。
Farook Hamzeh, Glenn Ballard & Iris D. Tommelein(2012) Rethinking Lookahead Planning to OptimizeConstruction Workflow. Lean Construction Journal 2012pp 15-34 Lean Construction Journal 2011/licenses/by-nc-nd/3.0/15 Rethinking Lookahead Planning to Optimize Construction WorkflowFarook Hamzeh1; Glenn Ballard2; Iris D. Tommelein3AbstractResearch Question: How to improve lookahead planning practices in the constructionindustry to increase the reliability of production planning?Purpose: To assess the performance of lookahead planning, advise a standardized practice tosupport a strong linkage between Lookahead planning and activity execution, and improve the reliability of production planning.Research Design/Method: This study employs case study analysis, industry interviews, and anindustry survey to assess the current implementation of lookahead planning on construction projects in North America, South America, and Europe.Findings: The study findings indicate the existence of non-compliance with Last Planner®System rules, inadequate lookahead planning and standardized practices, sluggish identification and removal of constraints, and absence of analysis for plan failures. Limitations: The authors’ active role on the projects used as case studies may constitute alimitation to the research methods and tools used. The industry survey may have not covered all companies applying the Last Planner System. The suggested framework should be custom tailored to different projects to cater for size, culture, etc. Implications: This research provides a framework for applying the Last Planner System rulesduring lookahead planning. It aims at increasing the success of the making activities ready, designing operations, and ultimately improving PPC.Value for practitioners: The study presents to industry practitioners applying the LastPlanner System a standardized framework for implementing lookahead planning on construction projects. The paper also highlights the use of two metrics to assess the performance of lookahead planning at a given point in time and to monitor performanceover a period of time or between projects.Keywords: Lookahead planning, production planning, production control, lean construction,the Last Planner System, construction planning.1 Corresponding Author- Assistant Professor, Department of Civil and Environmental Engineering, 406E Bechtel,American University of Beirut, Riad El Solh, Beirut 1107 2020, Lebanon, Farook.Hamzeh@.lb2 Research Director, Project Production Systems Laboratory andAssociate-AdjunctProfessor, Civil and Environmental Engineering Department, 215 McLaughlin Hall, University. of California,Berkeley, CA 94720-1712,USA, ballard@3 Professor, Dept. of Civil and Environmental Engineering, and Director, Project Production Systems Laboratory, 215-A McLaughlin Hall, University of California, Berkeley, CA 94720-1712, USA ,tommelein@Hamzeh, Ballard, & Tommelein: Rethinking Lookahead Planning to Optimize Construction WorkflowLean Construction Journal 2011/licenses/by-nc-nd/3.0/page 16 Paper type: Full PaperIntroductionArchitecture, Engineering, and Construction (AEC) processes are plagued with problemsassociated with variations that undermine project performance and disrupt workflow leadingto detrimental impacts on project’s duration, cost, and quality (Hamzeh et al. 2007, Hoppand Spearman 2008, Salem et al. 2006, and Crichton 1966). Organizations use a number ofdifferent methods to maintain consistency in production flow and to shield production fromvariations in internal business processes as well as the external environment. Thompson(1967) highlighted some of these methods including:•Forecasting•Buffering•SmoothingVarious forecasting methods are used to anticipate variations in internal processes andin inputs to production. However, forecasts cannot cater for all variations and have manylimitations: the more detailed a forecast is the more off it will be, the farther a forecastlooks into the future the less accurate it becomes, and forecasts are always wrong (Nahmias2009).Buffering is used to mitigate process variations on both the input and output sides. Inputs typically needed for successful execution of tasks include: information, prerequisitework, human resources, space, material, equipment, external conditions, and funds (Ballard& Howell 1994, Koskela 2000).Buffers can take on one of three main forms: time, inventory and capacity. Time buffersallocate slack to an activity, inventory buffers utilize extra stock to account for supplyvariations, and capacity buffers reserve extra capacity such as using overtime or maintainingmachinery used only when needed to accommodate surges in load.Smoothing variations in supply and demand is another method that organizations applysince buffering may not be enough to cater for all variations, is costly to apply, and may leadto complacency. An example of smoothing demand is leveling the work load or heijunka asadvocated in the Toyota Production System (Liker 2004).Although variation undermines project performance, production systems can be designed to reduce them and to manage residuals utilizing a combination of the abovementioned methods.A production system can be defined as a collection of people and resources (e.g., machinery, equipment, information) arranged to design and make a product (“goods” or“services”) of value to customers (Ballard et al. 2007). A cornerstone of a production systemis production management such as the Last Planner System, which has been successfullyimplemented on construction projects (Ballard and Howell 2004) to increase the reliability ofplanning, improve production performance, and create predictable workflow indesign andconstruction operations.On any project, the planning process can be plagued by various problems. Planning involves forecasts that can be inaccurate the further they project into the future (NahmiasHamzeh, Ballard, & Tommelein: Rethinking Lookahead Planning to Optimize Construction WorkflowLean Construction Journal 2011/licenses/by-nc-nd/3.0/page 17 2009). It is hard to execute work schedules when Planners push plans to frontline specialistswithout involving them in plan development. Short-term work plans developed on the basis ofwishful thinking and in absence of reliable promises from trade experts are more likely to fallshort during execution. And if causes of plan failures are not identified and dealt with in atimely fashion, further failures are bound to happen (Hamzeh 2009). Moreover, reliableplanning depends on effective constraint analysis and removal. Constraints are those prerequisites required to be present before an activity can start (e.g., previous work,information, labor, material, equipment, tools, space, weather, etc.). Managing constraintscan help optimize work plans by identifying resource conflicts and resolving them prior towork start. Without constraint removal, it is hard to manage and reduce work flow uncertainties that often cause process variations (Chua et al. 2003).Taking into account the challenges mentioned above, the Last Planner System advocatesthe following steps in project planning:•Plan in greater detail as you get closer to performing the work (Cohn 2006) •Develop the work plan with those who are going to perform the work•Identify and remove work constraints ahead of time as a team to make work ready andincrease reliability of work plans•Make reliable promises and drive work execution based on coordination and active negotiation with project participants•Learn from plan failures by finding root causes and taking preventive actions (Ballard,et al. 2009)Despite the advantages of this system (Alarcón and Cruz 1997, Gonzalez et al. 2008), the current practice on many construction projects shows a poor implementation oflookahead planning resulting in a wide gap between long-term planning (master and phaseschedules) and short-term planning (commitment/weekly work plans) reducing the reliabilityof the planning system and the ability to establish foresight.This paper presents an assessment of lookahead planning implementation as one processin the Last Planner System, highlights some inadequacies in operating the planning system,emphasizes the role of lookahead planning as a prime driver to the success of weekly workplanning, and suggests guidelines for performing lookahead planning pertaining to activitybreakdown, operation design, and constraint analysis.The Last Planner SystemThe Last Planner System as developed by Glenn Ballard and Greg Howell is a system forproduction planning and control used to assist in smoothing variations in construction workflow, developing planning foresight, and reducing uncertainty in construction operations. Thesystem originally tackled variations in workflow at the weekly work plan level but soonexpanded to cover the full planning and schedule development process from master scheduling to phase scheduling through lookahead planning to reach weekly work planning.Percent Plan Complete (PPC) is a metric used to track the performance of reliable promising at the weekly work plan level by measuring the percentage of tasks completedrelative to those planned. It thus helps assess the reliability of work plans and initiatesHamzeh, Ballard, & Tommelein: Rethinking Lookahead Planning to Optimize Construction WorkflowLean Construction Journal 2011/licenses/by-nc-nd/3.0/page 18 preparations to perform work as planned. PPC is not a direct measure of project progress, butrather a measure of the extent to which promises are kept, and hence the extent to whichfuture work load may be predictable. Previous research has found a correlation between PPCand labor productivity (Liu and Ballard 2008). Possible secondary impacts of PPC onimprovingwork safety and quality require further research (Ballard and Howell 1998, Ballard et al.2007). Despite the advantages of the LPS, research has shown that many organizations facesignificant hurdles when implementing the system (Ballard et al. 2007; Hamzeh, 2009; Vianaet al. 2010). Hamzeh (2011) presented a framework for successful implementation of the LastPlanner System on construction projects.However, when the entire Last Planner System (master scheduling, phase scheduling,lookahead planning, and weekly work planning) is executed and updated as designed, PPCshould be an indicator of project progress; i.e., PPC and progress should vary with each other.This claim can be expressed as a complex hypothesis; namely:H1: If lookahead tasks are drawn from a phase schedule structured toachieve the project end date and intermediate milestones, and iflookahead planning makes ready what SHOULD be done, and if weeklywork plans are formed from what CAN be done selected from whatSHOULD be done in the order of criticality without gaming the system, PPCwill vary with project progress.If we accept this hypothesis as an assumption, it follows that if PPC does not vary withproject progress, there is a broken link somewhere in the hypothesized chain. Figure 1 shows the Last Planner System where activities are broken down from phases(boulders) to processes (rocks) then to operations (pebbles) across four planning processeswith different chronological spans: master scheduling, phase scheduling, lookahead planning,and weekly work planning.Master scheduling is a front-end planning process that produces a schedule describingwork to be carried out over the entire duration of a project. It involves project-level activities and identifies major milestone dates mostly in relation to contract documents andthe owner’s value proposition (Tommelein and Ballard 1997).Phase scheduling generates a schedule covering each project phase such as foundations, structural frame, or finishing. In a collaborative planning setup the projectteam: (1) defines a project phase or milestone, (2) breaks it down into constituent activities,and (3) schedules activities backward from the milestone. After incorporating input fromdifferent project parties and identifying hand-offs between specialists, the team performsreverse phase scheduling back from important phase milestones (Hamzeh 2009, Ballard andHowell 2004).Lookahead planning is the first step in production control (executing schedules) and usually covers a six week time frame. Lookahead time periods vary with the type of workbeing performed and the context. (For example, in conceptual design, tasks cannot beforeseen at a detailed level very far in advance because of the phenomenon of emergence. Inplant shutdowns, the lookahead period extends to the end of the shutdown. In this research,the focus is on normal construction projects, and on those 4 to 6 week time frames arecommonly used in lookahead planning). At this stage, activities are broken down into theHamzeh, Ballard, & Tommelein: Rethinking Lookahead Planning to Optimize Construction WorkflowLean Construction Journal 2011/licenses/by-nc-nd/3.0/page 19 level of production processes/operations, constraints are identified, operations are designed,and assignments are made ready (Ballard 1997, Hamzeh 2009).Weekly work planning (WWP) also known as commitment planning represents the mostdetailed plan in the system, shows interdependence between the works of various specialistorganizations, and directly drives the production process. Plan reliability at this level ispromoted by making quality assignments and reliable promises so that the production unitwill be shielded from uncertainty in upstream operations. The work assignment is a detailedmeasurable commitment of completion. At the end of each plan period, assignments arereviewed to assess whether they are complete or not, thus measuring the reliability of theplanning. For incomplete assignments, analyzing the reasons for plan failures and acting onthese reasons is the basis of learning and continuous improvement (Ballard 2000). Figure 1: Planning processes in the Last Planner System.The Last Planner System relates to deliberative and situated action planning as described by Senior (2007) combining aspects of both worlds. On one hand, deliberativeplanning takes place at the master and phase scheduling level where a premeditated courseof action is specified in setting milestones and identifying handoffs. On the other hand, thelookahead and weekly work plans are closer to the situated planning model where plans takeHamzeh, Ballard, & Tommelein: Rethinking Lookahead Planning to Optimize Construction WorkflowLean Construction Journal 2011/licenses/by-nc-nd/3.0/page 20 into account changes in the environment affecting inputs and outputs of constructionactivities.However, a question remains unanswered: how can the AEC industry advance the implementation of the lookahead planning within the Last Planner System to improveconstruction workflow and the reliability of planning?Accordingly, this paper reports an assessment of the current implementation of the LastPlanner System in construction, presents analytical data, highlights concerns with the currentpractice, and lays out recommended procedures to perform lookahead planning aiming atproducing more reliable production plans.MethodologyThis paper summarizes research conducted to study the role of lookahead planning within the Last Planner System in improving construction workflow and increasing thereliability of planning. Research involves results from two construction projects and preliminary results from a survey addressing Last Planner implementation (Hamzeh 2009).Case study research was the methodology adopted in this study because:1. It is appropriate for answering questions pertaining to ‘how’ and ‘why’ whe n no control for behavioral events is required and when research focuses on contemporaryaffairs.2. It uses both quantitative and qualitative methods to explain phenomena.3. It utilizes multiple sources of evidence in a natural setting that encompasses temporaland contextual facets of the variables monitored.4. It uncovers the dynamics of events explaining the phenomenon under study.5. It provides qualitative understanding when arriving at conclusions and analyzing results (Meredith 1998, Stuart et al. 2002, Yin 2003).The case studies involve two health care projects in the United States. Both projects employed the Last Planner System for production control investing heavily in employeetraining and in different aspects of lean construction. The owner on both projects is a strongadvocate of lean and integrated project delivery systems. The authors also conducted someinterviews with industry practitioners who worked on these projects.The first author spent fourteen months on project one working for ten months as a researcher and four months as an intern. While he was more of an observer in the researcherposition, he had more input into the process while working as an intern helping the development of a planning process. The first author also spent around eight months onproject two helping in the implementation of the Last Planner System and applying a newsoftware application to manage the planning process.Prior to case study research, an industry-wide survey was conducted among Last PlannerSystem industry users in the US, south America, and Europe. The survey addressed engineersand managers working for owners, architects/engineers, and contractors. The companieswere identified with help of the Lean Construction Institute (LCI). The survey aimed atassessing the implementation of the system, informing research on obstacles faced in theHamzeh, Ballard, & Tommelein: Rethinking Lookahead Planning to Optimize Construction WorkflowLean Construction Journal 2011/licenses/by-nc-nd/3.0/page 21 current practice, and providing feedback required in shaping the formation of guidelines forimprovement.The research process follows an inductive reasoning scheme adjusted to the specific situation. Accordingly the research process comprised multiple steps of evaluating andassessing the current practice, developing guidelines for improvements, and testing thesesuggested guidelines. In collecting data (e.g., PPC historical project data, master scheduledata) several methods were employed such as: conducting short interviews, attending weeklyor pull/phase scheduling sessions, attending value stream planning sessions, and performingexercises to assess the performance of the lookahead process and weekly work planning.Case Study OneThe first case study is a 555-bed hospital and medical campus in San Francisco, California. The $1.7 billion project comprises a 16-story hospital including two below-gradefloors. This is a project to study because of:•implementing integrated project delivery (IPD) and integrated form of agreement (IFOA)•engaging project partners who are interested in experimenting with lean practices •applying Last Planner System for production planning and control,•utilizing target value design (TVD) to steer design towards meeting the owner’s valueproposition•using building information modeling (BIM) extensivelyAs explained above, we assume for the moment that if the Last Planner System is implemented correctly, PPC and project progress should vary together. To determine if theyin fact do vary together, and hence if implementation is correct, an investigation wasperformed to compare slips or gains on the master schedule with each update to weekly workplanning performance expressed in percent plan complete (PPC). This investigation comprisedan in-depth study of the master schedule built in Primavera P6 scheduling software including:•Monitoring project milestones with each update.•Tracking changes to the schedule in terms of rescheduling, adding activities, addingdetail into current activities, changing sequence/logic, altering durations, and addingmodules suggested during phase planning sessions.•Analyzing the incremental slip or gain on schedule with each update. Assessing the weekly work planning performance was performed by monitoring PPC witheach weekly update. To adequately compare weekly PPC and incremental schedule changeson the master schedule, an aggregate PPC figure was calculated over 3 or 4 weeks, which isthe average cycle for master schedule updates.Figure 2 shows the relationship between percent plan complete (PPC) and the incremental schedule difference in days (+ is schedule delay and – is schedule gain). If systemimplementation was correct (drawing tasks into the weekly work plan that are critical withoutgaming the system), the higher the PPC the lower the schedule slip should be. However,results show a weak correlation of 0.28 and a covariance of 1.01 between PPC and negativeHamzeh, Ballard, & Tommelein: Rethinking Lookahead Planning to Optimize Construction WorkflowLean Construction Journal 2011/licenses/by-nc-nd/3.0/page 22 incremental schedule difference. Therefore, a clear relationship between weekly performance and overall schedule performance was not found.Moreover, the highlighted area in Figure 2 shows an increase in project delays (+ increment) for a higher PPC when more work was actually completed on the weekly schedule3. These results suggest that in Case 1 project, there is no evidence that variation inthe incremental schedule difference can be explained by PPC. This may indicate a poorlinkage between weekly work plans and the master schedule.Since earned value analysis is used to measure progress it may sometimes tempt teamsto work out of sequence to maximize progress gains in a certain period. While this may havean impact on the relationship between PPC and incremental schedule difference, it is still inviolation of the caveats stipulated in hypothesis H1 and a result of an incorrect developmentof the master schedule into a lookahead plan and an incorrect development of the lookaheadplan into a weekly work plan. That is why both working out of sequence and gaming thesystem are indications of poor implementation of the LPS and a poor linkage between weeklywork plans and the master schedule.‐80‐60‐40‐20204060800%10%20%30%40%50%60%70%80%90%100%25‐Oct‐2007 8‐Nov‐2007 22‐Nov‐2007 6‐Dec‐2007 20‐Dec‐2007 3‐Jan‐2008 17‐Jan‐2008 31‐Jan‐2008 14‐Feb‐2008 28‐Feb‐2008 13‐Mar‐2008 27‐Mar‐2008 10‐Apr‐2008 24‐Apr‐2008 8‐May‐2008 22‐May‐2008 5‐Jun‐2008 19‐Jun‐2008 3‐Jul‐2008 17‐Jul‐2008 31‐Jul‐2008 14‐Aug‐2008 28‐Aug‐2008 11‐Sep‐2008 25‐Sep‐20089‐Oct‐200823‐Oct‐2008 PPC Incremental Schedule Difference (days)Figure 2: The relationship between Percent Plan Complete (PPC) and incrementalschedule difference for case study 1Case Study TwoThe second case study project involved rehabilitation of 23 buildings, new constructionof 14 buildings, and landscape works for Fort Baker Retreat Group LLC at Fort Baker, Sausalito, California (Quakenbush 2008). The project budget was $103 million. This project3 While the two negative increments may be due to optimistic updating at the user level, the positive and negativeincrements do not correlate with PPC figures.Hamzeh, Ballard, & Tommelein: Rethinking Lookahead Planning to Optimize Construction WorkflowLean Construction Journal 2011/licenses/by-nc-nd/3.0/page 23 was chosen because the schedule was broken down into separate phases that were monitoredand recorded.This study focuses on the production management practices performed on the rehabilitation section of the project where the general contractor (GC) used the Last PlannerSystem to manage production. The GC developed the master schedule for the project usingphase scheduling sessions in collaboration with trade contractors and subcontractors. Theteam focused on the project handover and everything in between project start and projecthandover was decided using pull sessions. The GC continuously incorporated results fromthese sessions into the master schedule that was built in Microsoft Project and updated on aweekly basis. This schedule was developed to allow for a flow of construction trades from onebuilding to another. The project team used the Last Planner System to develop and manageweekly work planning based on the master schedule. Although the team did not applylookahead planning, they conducted weekly meetings for last planners who。