土木专业英文翻译

外文翻译

Discuss the construction temperature and crack of the

concrete lightly

The summary Through observation live for many years, through consulting the monograph about stress within the concrete, explain to concrete temperature reason , on-the-spot concrete control and measure , prevention of crack of temperature that crack produce.

Keyword: Concrete;Temperature stress;Crack ;Control

1. The concrete occupies the important position in modern engineering construction. But today, the crack of the concrete is comparatively general, the cracks are nearly omnipresent in the science of bridge building. Though we take various kinds of measures in constructing, careful, but the crack still occurs now and then. Tracing it to its cause, it is one of them incompletely that our change to concrete temperature stress pays attention to. In the large volume concrete, temperature stress and temperature control are significant. This is mainly because of the reason of two respects. First of all, concrete often appear the temperature crack in not constructing, influence the globality and durability of the structure. Secondly, in the course of operating, the temperature change has remarkable influence that can't be ignored on the stress state of the structure. We meet to construct temperature crack in mainly, so only to origin cause of formation and treatment measure, concrete of crack make a discussion in constructing this text.

Reason of a crack

Have many kinds of reasons to produce the crack in the concrete, it is mainly the changes of temperature and humidity, fragility and disparity of the concrete, and the structure is unreasonable, the raw materials is not up to standard (if the alkali

aggregate react), the template is out of shape, the foundation does not subside etc. evenly . The cement emits a large amount of heat of hydration when the concrete is hardenned, inside temperature is rising constantly, cause the stress of drawing on the surface. In the course of lowering the temperature , is it congeal foundation pay restrain to mix always later stage, will present the stress of drawing within the concrete . Reducing of temperature can surface cause heavy stress of drawing very in concrete too. When these draw the stress and go beyond resisting the ability of splitting of concrete , namely will present the crack . A lot of inside humidity of concrete change very light or change relatively slow, surface humidity might change heavy the violent change takes placing. Such as maintaining thoroughly, when getting wetter when not doing,contract surface there aren't deformation doing, often cause the crack too. The concrete is a kind of fragility material , tensile strength is about 1/10 of the compression strength, is it carry on one's shoulder or back limit when draw out of shape to have *104 only , is it carry on one's shoulder or back limit location when stretch out of shape to there is *104 to add for a long time to add a short time. Because raw materials even, water dust than unstable, transport and build phenomenon of emanating of course, its tensile strength is not even in the same concrete, a lot of resist the ability of drawing very low, it is apt to present the weak position of the crack. Among armored concrete , draw stress to undertake by reinforcing bar mainly , concrete bear stress of keeping just. Or reinforcing bar mix if edge position gone to to congeal present the stress of drawing in the structure in plain concrete, must rely on the concrete oneself to bear . Require to avoid the stress of drawing or only very small stress of drawing appears of the the general design. But the concrete is cooled from maximum temperature to the steady temperature of operating period in constructing, often cause sizable to draw the stress within the concrete. The temperature stress can exceed other outsides and load the stresses caused sometimes, know change law , temperature of stress for carry on reasonable

structural design and construct extremely important.

Analysis of 2 temperature stresses

Can be divided into following three stages according to the forming process of the temperature stress:

(1)It is early: Build concrete is it is it over basically to send out heat to cement to begin , generally one one day by oneself. Two characteristics at this stage, first, the cement emits a large amount of heat of hydration, second , mix and congeal the changing sharply of elastic model quantity. Because of the change of elastic model quantity , form the remaining stress in the concrete in this period.

(2)Middle period: Up till the concrete is cooled until stability temperature from cement send out heat function basically when expiring, in this period, the temperature stress is mainly because the cooling of the concrete and external temperature change cause, these stresses and remnants stresses that is formed in early days are superposed , mix and congeal the elastic mould amount that goes to and does not change much during this period.

(3)Later period: Operation period after the complete cooling of concrete. Temperature stress whether external temperature change cause mainly, these stresses and first two kinds of remnants stresseses are changed and added .

Can be divided into two kinds according to the reason why the temperature stress causes:

(1)Spontaneous stress: There are not any restraint or totally static structure at the border, if inside temperature is non-linear distribution, temperature stress appearing because structure restrains from each other. For example, the body of mound of the bridge, the physical dimension is relatively large, surface temperature is low when the concrete is cooled, inside temperature is high, present the stress of drawing on the surface, present the stress of pressing in the middle.

(2)Restrain the stress: All of the structure ones or it restrain external one some

border,can't out of shape and stress not cause not free. Such as case roof beam roof concrete and guardrail concrete.

This two kinds of temperature stresses draw back stresses caused to act on with the doing of concrete together frequently. It is a more complicated job to want to analyse the distribution , size of the temperature stress accurately according to known temperature. In case of great majority , need to rely on the model test or the number value to calculate. To is it make temperature stress have sizable limp to creep concrete, at the stress accounting temperature, must consider the influence that creep , calculate concretly that no longer states thinly here.

Control and preventing the measure of the crack of 3 temperature

For prevent crack , lighten temperature stress can from control temperature and is it is it set about to restrain terms from two to improve.

The measure of controlling temperature is as follows:

(1)Is it improve aggregate grade mix , is it do rigid concrete to spend , mix mixture to adopt, is it guide angry pharmaceutical or plastification pharmaceutical ,etc. measure in order to reduce cement consumption of concrete to add;

(2)Add water or the water to cool the broken stone in order to reduce the temperature of building of the concrete while mixing and shutting the concrete;

(3)Reduce the thickness of building while building the concrete on hot day, utilize and build the aspect to dispel the heat;

(4)Bury the water pipe underground in the concrete, enter the cold water to lower the temperature openly;

(5)Stipulate rational form removal time, the temperature keeps warm the surface while lowering suddenly, in case that the rapid temperature gradient takes place in the concrete surface;

(6)The concrete with medium and long-term and exposed construction builds a

piece of surface or thin wall structure, take the measure of keeping warm in cold season;

The measure of improving condition of restraining is:

(1)Divide and sew and divide one rationally ;

(2)Prevent the foundation from rising and falling too big;

(3)Rational arrangement construction process, prevent the too big discrepancy in elevation and side from exposing for a long time;

In addition, improve the performance of the concrete and improve and resist the ability of splitting, strengthen maintenance , prevent the surface from being done and contracted , especially guarantee the quality of the concrete is very important to preventing the crack, should pay special attention to avoiding producing and running through the crack , the globality resumed its structure after appearing is very difficult, so should rely mainly on preventing the emergence of the running through crack while constructing.

In construction of concrete , for raise turnover rate of template , demand concrete form removal as soon as possible that build newly often. Should consider form removal time properly when concrete temperature is higher than the temperature, so as not to cause the superficial early crack of concrete. Building the early form removal newly, cause very large stress of drawing on the surface, the phenomenon that " temperature is assaulted " appears. Build initial stage in concrete, because heat of hydration is sent out, the surface causes sizable to draw the stress, surface temperature is also higher than temperature at this moment, remove the template at this moment , surface temperature is lowered suddenly, must cause temperature gradient , thus add and draw the stress on the surface , change and add with the heat of hydration stress, in addition, the concrete dries and contracts , the superficial stress of drawing reaches very great number value, have danger of causing the crack, but cover a light-duty heat insulator with on the surface in time

after removing the template , for instance foam sponge ,etc., for prevent concrete surface from produce the too big stress of drawing, have remarkable results.

Add muscle influence to large volume temperature stress of concrete very light , because large volume concrete include muscle to be rate very much low. Just have influence on the general armored concrete. On terms that temperature is not very high and the stress is less than limit of surrendering, every performance of the steel is steady, and have nothing to do with stress state , time and temperature. Line bloated coefficient of steel and concrete line bloated coefficient difference very light, take place little internal stress very only between the two while changing in temperature. Because elastic mould amount of steel concrete elastic mould 7~15 of quantity, reach as interior concrete stress tensile strength and when fracturing, the stress of the reinforcing bar will not exceed 10000kg/cm2. . So is it is it prevent tiny appearance difficulty very much of crack from to make use of reinforcing bar to want among concrete. But the crack in the structure generally becomes numerous, the interval is little, the width and depth are smaller after adding the muscle. And if diameter of reinforcing bar detailed and when interval dense, to improve concrete resist result of person who split better. Concrete and surface , armored concrete of structure can take place detailed and shallow crack often, among them the great majority belong to and do and draw back the crack. Though this kind of crack is generally all relatively light, it stills have certain influence on the intensity and durability of the structure.

In order to guarantee concrete project quality , prevent fracturing , improve the durability of the concrete, use the admixture to reduce one of the measures that fractures correctly. Whether is it reduce water is it split pharmaceutical to defend , I summarize his main function in practice to use.

(1)There is pore Dao of a large number of mao in the concrete , produce capillary tension in the capillary after water is evaporated, make concrete is it contract out of shape to do. Increasing the thin aperture of hair can reduce the

capillary surface tension , but will make the intensity of concrete reduce . This surface tension theory has already been confirmed in the world as far back as the sixties.

(2)Water dust than influence important factor that concrete shrink, is it reduce water is it split pharmaceutical can make concrete water consumption reduce by 25% to defend to use.

(3)Cement consumption important factor, concrete of person who shrink too, is it add and subtract water is it split concrete reducible 15% of the cement consumption on terms that keep the intensity of concrete of pharmaceutical to defend to mix, its volume is supplemented by increasing aggregate consumption.

(4)Reduce water is it split pharmaceutical can improve consistency of grout , reduce concrete secrete ink to defend, reduce and sink and draw back deforming.

(5)Improve glueing the strength of forming of the grout and aggregate, the concrete improved resists the performance of splitting.

(6)Concrete is it produce stress of drawing to restrain from while shrinking, crack when drawing the stress and is greater than concrete tensile strength can produce. Reduce water is it split pharmaceutical effective concrete tensile strength of improvement very to defend , improve resisting the performance of splitting of concrete by a wide margin.

(7)It can make the concrete density good to add the admixture to mix , can improve resisting carbonization of concrete effectively , reduce carbonization to shrink.

(8)Is it reduce water is it split slow coagulation time proper concrete under pharmaceutical to defend , on the basis of preventing the fast water of cement from sending out heat effectively to mix, prevent the plasticity shrink that brings because the cement is not congealed for a long time from increasing.

(9)Mix admixture concrete and getting easy and kind , surface easy to feel flat ,

form little membrane, reduce the moisture to evaporate, reduce drily and shrink. A lot of admixture all have the functions of slow coagulation , increasing and apt , improvement plasticity, the experiment that we should carry on in this respect more in the project practice is compared with and studied, than lean against not improving terms more simple,may getting simple and more direct, economy.

Early maintenance of 4 concrete

Practice has proved , the common crack of concrete , most is the surface crack of different depth, main reason its whether temperature gradient cause cold temperature of area lower too easy to form crack suddenly. So say the warm - keeping of the concrete is especially important to preventing the early crack of surface.

From the viewpoint of temperature stress, should reach and require to keep warm followingly:

1)Prevent concrete internal and external temperature poor and concrete surface gradient from , prevent the surface crack.

2)Prevent concrete from to be ultra and cold , should is it is it make the minimum temperature is not lower than the steady temperature of concrete service time construction time in concrete to try to try one's best.

3)Prevent the old concrete subcooling , in order to reduce the restraint among the old and new concrete.

The early maintenance of the concrete, the main purpose lies in keeping the suitable warm and humid condition , in order to get the result of two respects, on the other hand make the concrete avoid the invasion and attack of the unfavorable and warm , humidity out of shape, the ones that prevent from harmfully are cold to contract and do to contract. On one hand make cement water function go on smoothly , is in the hope of reaching the intensity designed and resisting the ability of splitting.

The suitable warm damp condition is interrelated. Mix warm - keeping measure paid to congeal often protect wet results too. Analyse , water concrete include moisture can meet demand , cement of water have enough and to spare newly theoretically. But because the reason of evaporating etc. often causes losses of the moisture, thus postpone or hinder water of the cement from, the surface concrete receives this kind of adverse effect easiestly and directly. Key period when maintained in initial a few days after so the concrete is built, should pay attention to conscientiously in constructing.

Conclusions

Construction temperature and relation of crack in concrete the above carry on preliminary discussion of theory and practice, though the academia has different theories to origin cause of formation and computing technology of the concrete crack, but to concrete prevention and improving the measure suggestion to relatively unify , application in practice result fine too at the same time, concrete to is it observe , compare more more by us to want in constructing, analyse more , summarize more after going wrong , combine many kinds of prevention and deal with the measure, the crack of the concrete can be avoided.

2.Quality control of waterproof concrete construction

Combined with experience, from formwork design, fabrication and installation, assembing reinforoement, pouring and curing of concrete and other aspects construction technology of fair-faced concrete is introduced as well as quality control measures and standards in order to reduce engineering cost to acquire satisfied economic and social benefits.

The factors of influening waterproof- concrete quality are very many

Any links does not pay attention to the water-proof concrete of field loss hinders the water function without exception jointly with degree.Engineering construction in the basement adopts secondary form board fabrication and installation, reinforced bar

fabrication and bind, concrete stirring and mixing system and transport, concrete concrete covibration beat with a stick, construction joint practice, concrete curing and dismantle model and beingready for backfill and so on aspects.These are very critical to quality method to ensure that water-proof concrete self water-proof, and the way of practice has wan out.

Method being under construction

2.1 Fabrication and Installation

According to the concrett of closely knit , demand of reason why to form board since the water-proof also concrete have made and have assembled corresponding rise is special , be to require that not leaving out thick fluid , firm closely knit block of wood deformation , water absorption Character should be small and ought to give priority to select and using bamboo slab rubber form board or the steel form.. Strict control form board room gap size, necessary exceeding 2 mms uses foam rubber or plastic to squeeze a crack in , porous form board nonutility without exception to board face Be ready for wall post at the same time rotting the prevention and cure job Adopt the cement mortar pouring same ,indicia in before the root segment sticking the foam rubber or plastic strip , the bottom puts on a cement mortar , concrete a concrete, first 5 cm ~ 10 cm. Since water-proof, concrete structure wall thickness is mostly more infertile .Be to ensure that component geometry dimension , Chang adopt the inside and outside bolt to pull the measure meeting attention to, responds to on play receive bolt centre interpose stop water iron plate, to prevent water from forming pilotage passage along bolt leakage.

2.2 Assembing reinforoement

Water-proof concrete structure has demanding as follows to the reinforced bar

1) reinforced bar should adopt twisted steel as far as possible , increases by hold

wrap a force composing in reply a water ability

2) reinforced bars connect should try one's best to adopt to solder connection , stop using and being needless to bind connection to the full

3) when binding a reinforced bar, the iron wire head responds to inner bending.

4) strict control reinforced bars protective layer thickness.

Minimal thickness of water-proof concrete reinforced bar protective layer is not smaller than 25 mms , the protective layer welcoming water surface especially inadmissibility to disappoint error,

. The iron wire and reinforced bar that application buries in advance within mortar piece while

using mortar heel block as protective layer, are bound

solid .When the cavalry puts up the fixed reinforced bar if adopt a reinforced bar, Ying Jia also solders water iron plate or fixation just goes ahead, to strengthen water-proof effect in the

heel block.This project uses new materials nylon to have fixed there is an effect's had guarded against reinforced bar protective layer deviation piece big mass common failings.

The concrete stirring and mixing makes and transports

Since the water-proof concrete requires that higher closely knit , reason why stir and mix system also need to have the fairly good homogeneity , should be ready for burning as follows almost for this purpose

1) ensures that mixing time , mixing at every time are secondary jump into a expect the general ejection of compact block of wood less than 2 mins.

2) should use the apposition agent , the solution queen who should manufacture certain thickness from apposition agent adds the mixer inner, the dried powder or high concentration solution will add an agent extra not to adds the mixer inner directly ,prevent from mixing is uneven but part

concentrates, both lose the apposition agent effect, and affect concrete mass.

3) responds to the assured source of life degree having a spot test on the admeasurement concrete at the regular intervals collapsing in the process being under construction , construction is middle

if Yu rains or other cause, respond to the ratio determining whose water ratio, and adjusting the composition being under construction in time when change happened in sandstone moisture content.

4) project uses the commodity concrete , has boundary have raised a concrete stirring mass and of all kinds effect apposition agent adulterating falls when amounts , the water ash having controlled a concrete strictly collapsing.

5) concretes concrete adopt a pump to have given handicraft , effective avoiding a concrete producing the phenomenon isolating Mi Shui and leaving out thick fluid in the

process of transportation.

2.4 Matters needing attention in being under construction

1) construction school assignment soft and floury is divided .Water-proof concreting should stratify strictly being in progress, and a continuous construction iscompletedThe front and back and high and low connect between the tier should subjugate within the cement initial setting

time,For this purpose ,with handling a worker dividing into several, at the same time each other, school assignment group faces or it is all right for each other, carry on the back .

2)Achieve strictly fixed point determines the amounts of the components of a substance material down According to the vehicle capacities stratifying concrete altitude and the means of transport, the quantify carrying out fixed point strictly is able to go down one important ring expecting that this is to improve water-proof concreting mass.

3) insist that you go down material opening the door or use string to expect that under barrel (chute)Be to prevent a cement paste from parting from aggregate for , to expect that liberty should not exceed 1.5 ms now and then highly under water-proof concrete。The water-proof structure reinforced bar is concentrated Should concrete altitude when higher , respond to according to the material stipulating that you go down material opening the door on form board or using string of barrels (chute) to fall, prevent a cement paste from parting from aggregate for , avoid at the same time also the cement paste or the concrete

accumulating the place and cement paste alternating in the reinforced bar loosely splashing sticky Yu form board with outsideNow that material is difficult under bringing about a later, the surface affecting structure glossy , becomes in the future leakage hidden trouble.

4) concretes vibrating beat one important ring being to ensure that the concrete is closely knit , defend against to seep with a stick. Also, should adopt fixed point vibrating , handle meticulously on basis expecting that under determining the amounts of the components of a substance homogeneously in fixed point .Pay attention to high and low tier of linking up

Now that needing to prevent from miss and vibrating , not vibrating enough , being going to prevent a fault from vibrating again, Need to forbid using prying the method coming to aid to vibrate moving a reinforced bar or shaking a reinforced bar especially, such separates to making the front already concrete the reinforced bar and concrete shaking the reality part , causes serious consequences.

5) being ready for the assured source of life degree taking over thick fluid measure , adjusting in time to collapse seriously .Average water-proof concrete structure construction, the construction joint being under construction respectively , composing namely on erecting wall sells be bottom board and vertical wall at reduced prices.Should irrigate thick a layer of 5 cm ~ 10 cms surname indicia cement

mortars in seam place first linking up closely knitting tier, in order to ensuring that the seam place vibrates when concrete vertical wall.Simultaneous , improve step by step with concrete an altitude'.Should fall off step by step with the water yield , diminish collapsing to fall degree prevent from concrete insist to be short but the cement paste is partial to much phenomenon to aggregate appearing on upper part.

2.5 The method of Construction joint

The construction joint is one of water-proof architectural weak link. The construction joint is one of water-proof architectural weak link. Should stop staying or not staying to the full. equipment or props up conditional restricting of model, may then behind the agreement

collecting a design organ, on the wall stipulating that lienable level of location construction joint , sort keep vertical strokes getting along in all above 200 bottom board .Adopt new handicraft expansibility in the project rubber water just brings handling the construction joint method , substituting method in common use , anxiously expecting the dyadic construction joint of mouth , at any rate dyadic construction joint , flat mouth construction joint such as and so on .Water proofing is in no lienable construction joint of perpendicularity direction like the concrete , rubber stops in having set up the construction joint irrigating belt , perpendicularity directionthe day afer tomorrow between the main building and the skirt building interposing expansibility in seam location water belt or steel plate stops water belt.weak link of water-proof structure, respond to specially-assigned person conscientiously , handle meticulously . Ensure mass to be under construction in construction. Adopt to stop having not to miss and not soldering time water steel plate, adopt rubber water belt just should be solid without fail reliably in receiving long time will

connect using special use glue to paste. When only think that concreting accepts

2.6 Dismantling model and curing of concrete

The water-proof concreting queen maintains goodness and badness working, not only affecting

the intensity arriving at a concrete, moreover the impervious function affecting to the concrete. Evidence , water-proof concrete early phase dehydration or curing process lack for water , will reduce whose impervious function by a wide margin. Water-proof concrete curing

responds to the block of wood less than 14 ds.

The water-proof concrete dismantles a model demanding to be unable to compare high , dismantle model time unsuitable untimely, respond to when dismantling a model handle meticulously , prevent an iron rod from using to pry, stiffly, that the sledgehammer is knocked suddenly

and forcibly pries , uses a concrete meet with destroy

2.7 Do good well at backfill

Water-proof architectural backfill is a final working procedure , it be sometimes ignored , this is a very big faults in fact under the ground.When the water-proof structure job is over queen responds to the construction carrying out backfill immediately.Most important ,we should take backfill seriously self mass; Secondly, backfill varia and ponding should clear up the pit bottom in the front , respond to densification with layers when backfill. Water-proof structure vicinity layer pounds true backfill , self is a reliable and economical as well water proofing drapery under the ground. In project basement engineering construction Shanghai,since organizing water proofing down to earth strictly with all above seven passes, the concrete is under construction , effect is comparatively ideal.The percolating water phenomenon does not appear.

Conclusions

Construction temperature and relation of crack in concrete the above carry on

preliminary discussion of theory and practice, though the academia has different theories to origin cause of formation and computing technology of the concrete crack, but to concrete prevention and improving the measure suggestion to relatively unify , application in practice result fine too at the same time, concrete to is it observe , compare more more by us to want in constructing, analyse more , summarize more after going wrong , combine many kinds of prevention and deal with the measure, the crack of the concrete can be avoided.

浅论混凝土的施工过程中温度与裂缝控制

摘要:本文通过多年的现场观察,通过查阅有关混凝土内部应力方面的专著,对混凝土温度裂缝产生的原因、现场混凝土温度的控制和预防裂缝的措施进行等进行阐述。

关键词:混凝土;温度应力;裂缝;控制

1 混凝土在现代工程建设中占有重要地位。而在今天,混凝土的裂缝较为普遍,在桥梁工程中裂缝几乎无所不在。尽管我们在施工中采取各种措施,小心谨慎,但裂缝仍然时有出现。究其原因,我们对混凝土温度应力的变化注意不够是其中之一。

在大体积混凝土中,温度应力及温度控制具有重要意义。这主要是由于两方面的原因。首先,在施工中混凝土常常出现温度裂缝,影响到结构的整体性和耐久性。其次,在运转过程中,温度变化对结构的应力状态具有显著的不容忽视的影响。我们遇到的主要是施工中的温度裂缝,因此本文仅对施工中混凝土裂缝的成因和处理措施做一探讨。

1.1 裂缝的原因

混凝土中产生裂缝有多种原因,主要是温度和湿度的变化,混凝土的脆性和不均匀性,以及结构不合理,原材料不合格(如碱骨料反应),模板变形,基础不均匀沉降等。

混凝土硬化期间水泥放出大量水化热,内部温度不断上升,在表面引起拉应力。后期在降温过程中,由于受到基础或老混凝上的约束,又会在混凝土内部出现拉应力。气温的降低也会在混凝土表面引起很大的拉应力。当这些拉应力超出混凝土的抗裂能力时,即会出现裂缝。许多混凝土的内部湿度变化很小或变化较慢,但表面湿度可能变化较大或发生剧烈变化。如养护不周、时干时湿,表面干缩形变受到内部混凝土的约束,也往往导致裂缝。混凝土是一种脆性材料,抗拉强度是抗压强度的1/10左右,短期加荷时的极限拉伸变形只有(0.6~1.0)×104,长期加荷时的极限位伸变形也只有(1.2~2.0)×104.由于

原材料不均匀,水灰比不稳定,及运输和浇筑过程中的离析现象,在同一块混凝土中其抗拉强度又是不均匀的,存在着许多抗拉能力很低,易于出现裂缝的薄弱部位。在钢筋混凝土中,拉应力主要是由钢筋承担,混凝土只是承受压应力。在素混凝土内或钢筋混凝上的边缘部位如果结构内出现了拉应力,则须依靠混凝土自身承担。一般设计中均要求不出现拉应力或者只出现很小的拉应力。但是在施工中混凝土由最高温度冷却到运转时期的稳定温度,往往在混凝土内部引起相当大的拉应力。有时温度应力可超过其它外荷载所引起的应力,因此掌握温度应力的变化规律对于进行合理的结构设计和施工极为重要。

1.2 温度应力的分析

根据温度应力的形成过程可分为以下三个阶段:

(1)早期:自浇筑混凝土开始至水泥放热基本结束,一般约30天。这个阶段的两个特征,一是水泥放出大量的水化热,二是混凝上弹性模量的急剧变化。由于弹性模量的变化,这一时期在混凝土内形成残余应力。

(2)中期:自水泥放热作用基本结束时起至混凝土冷却到稳定温度时止,这个时期中,温度应力主要是由于混凝土的冷却及外界气温变化所引起,这些应力与早期形成的残余应力相叠加,在此期间混凝上的弹性模量变化不大。

(3)晚期:混凝土完全冷却以后的运转时期。温度应力主要是外界气温变化所引起,这些应力与前两种的残余应力相迭加。

根据温度应力引起的原因可分为两类:

(1)自生应力:边界上没有任何约束或完全静止的结构,如果内部温度是非线性分布的,由于结构本身互相约束而出现的温度应力。例如,桥梁墩身,结构尺寸相对较大,混凝土冷却时表面温度低,内部温度高,在表面出现拉应力,在中间出现压应力。

(2)约束应力:结构的全部或部分边界受到外界的约束,不能自由变形而引起的应力。如箱梁顶板混凝土和护栏混凝土。

这两种温度应力往往和混凝土的干缩所引起的应力共同作用。

要想根据已知的温度准确分析出温度应力的分布、大小是一项比较复杂的

工作。在大多数情况下,需要依靠模型试验或数值计算。混凝土的徐变使温度应力有相当大的松驰,计算温度应力时,必须考虑徐变的影响,具体计算这里就不再细述。

1.3 温度的控制和防止裂缝的措施

为了防止裂缝,减轻温度应力可以从控制温度和改善约束条件两个方面着手。

控制温度的措施如下:

(1)采用改善骨料级配,用干硬性混凝土,掺混合料,加引气剂或塑化剂等措施以减少混凝土中的水泥用量;

(2)拌合混凝土时加水或用水将碎石冷却以降低混凝土的浇筑温度;

(3)热天浇筑混凝土时减少浇筑厚度,利用浇筑层面散热;

(4)在混凝土中埋设水管,通入冷水降温;

(5)规定合理的拆模时间,气温骤降时进行表面保温,以免混凝土表面发生急剧的温度梯度;

(6)施工中长期暴露的混凝土浇筑块表面或薄壁结构,在寒冷季节采取保温措施;

改善约束条件的措施是:

(1)合理地分缝分块;

(2)避免基础过大起伏;

(3)合理的安排施工工序,避免过大的高差和侧面长期暴露;

此外,改善混凝土的性能,提高抗裂能力,加强养护,防止表面干缩,特别是保证混凝土的质量对防止裂缝是十分重要,应特别注意避免产生贯穿裂缝,出现后要恢复其结构的整体性是十分困难的,因此施工中应以预防贯穿性裂缝的发生为主。

在混凝土的施工中,为了提高模板的周转率,往往要求新浇筑的混凝土尽早拆模。当混凝土温度高于气温时应适当考虑拆模时间,以免引起混凝土表面的早期裂缝。新浇筑早期拆模,在表面引起很大的拉应力,出现“温度冲击”

现象。在混凝土浇筑初期,由于水化热的散发,表面引起相当大的拉应力,此时表面温度亦较气温为高,此时拆除模板,表面温度骤降,必然引起温度梯度,从而在表面附加一拉应力,与水化热应力迭加,再加上混凝土干缩,表面的拉应力达到很大的数值,就有导致裂缝的危险,但如果在拆除模板后及时在表面覆盖一轻型保温材料,如泡沫海棉等,对于防止混凝土表面产生过大的拉应力,具有显著的效果。

加筋对大体积混凝土的温度应力影响很小,因为大体积混凝土的含筋率极低。只是对一般钢筋混凝土有影响。在温度不太高及应力低于屈服极限的条件下,钢的各项性能是稳定的,而与应力状态、时间及温度无关。钢的线胀系数与混凝土线胀系数相差很小,在温度变化时两者间只发生很小的内应力。由于钢的弹性模量为混凝土弹性模量的7~15倍,当内混凝土应力达到抗拉强度而开裂时,钢筋的应力将不超过100~200kg/cm2..因此,在混凝土中想要利用钢筋来防止细小裂缝的出现很困难。但加筋后结构内的裂缝一般就变得数目多、间距小、宽度与深度较小了。而且如果钢筋的直径细而间距密时,对提高混凝土抗裂性的效果较好。混凝土和钢筋混凝土结构的表面常常会发生细而浅的裂缝,其中大多数属于干缩裂缝。虽然这种裂缝一般都较浅,但它对结构的强度和耐久性仍有一定的影响。

为保证混凝土工程质量,防止开裂,提高混凝土的耐久性,正确使用外加剂也是减少开裂的措施之一。例如使用减水防裂剂,笔者在实践中总结出其主要作用为:

(1)混凝土中存在大量毛细孔道,水蒸发后毛细管中产生毛细管张力,使混凝土干缩变形。增大毛细孔径可降低毛细管表面张力,但会使混凝土强度降低。这个表面张力理论早在六十年代就已被国际上所确认。

(2)水灰比是影响混凝土收缩的重要因素,使用减水防裂剂可使混凝土用水量减少25%。

(3)水泥用量也是混凝土收缩率的重要因素,掺加减水防裂剂的混凝土在保持混凝土强度的条件下可减少15%的水泥用量,其体积增加骨料用量来补充。

科技英语翻译的原则_方法及技巧.

翻译是把一种语言里已经表达出来的事物用另一种语言准确流畅地进行重新表达的过程。与其他题材的文章相比,科技专业文章在内容、表达形式和风格上有很大的差别,具有科技性强、专业性强、逻辑严密、表达要求简练的特点,在翻译上力求准确全面、严谨明确和通顺简练。 1科技英语翻译遵循的基本原则 从科技文章的特点来看,大多具有以下几个特征:述说事理、逻辑性强、结构严密、术语繁多,语言严谨、数据精确。这就要求译文必须概念清楚、条理分明、逻辑正确、数据无误,尤其对定义、定律、公式、图表、结论等更应特别注意。科技英语作为特殊英语的一个分支,在词汇构成、遣词造句等方面都有其自身的特点,其语法结构不十分严密、语言习惯和汉语也有不少差别、词汇量大、词语繁多,因此科技英语翻译起来比较困难。另外,科技文章比较重视叙事逻辑上的连贯及表达上的明晰与畅达; 避免行文晦涩,避免表露个人感情,避免论证上的主观随意性。因此,科技英语翻译力求少用或不用描述性形容词以及具有抒情作用的副词、感叹词及疑问词,而是大量使用科技词汇、专业技术用语,译者应尊重客观事实,不能随意改动数据、回避不易翻译的文字,更不能加进自己的主观想象,进行自由翻译。 我国著名翻译家严复提出的“信、达、雅”三准则一直为不少翻译工作者所接受。 “信”指的是译文要忠实于原文,“达”是指译文的通顺达意,“雅”指的是译文的用词修辞。三准则体现了译文和原文信息等值这一基本要领。 “信、达、雅”的翻译准则对各种英语文体的翻译实践都具有指导意义,是衡量一篇译文好坏的标准,也同样适用于科技文献的翻译。由于科技文章特有的文体特征,与其他类文章相比,其“达”和“雅”的内涵不同,它要求在准确传达信息的基础上,使译文更加简洁明快,流畅通顺。2科技英语翻译的基本方法

土木工程专业英语翻译

a common way to construct steel truss and prestressed concrete cantilever spans is to counterbalance each cantilever arm with another cantilever arm projecting the opposite direction,forming a balanced cantilever. they attach to a solid foundation ,the counterbalancing arms are called anchor arms /thus,in a bridge built on two foundation piers,there are four cantilever arms ,two which span the obstacle,and two anchor arms which extend away from the obstacle,because of the need for more strength at the balanced cantilever's supports ,the bridge superstructure often takes the form of towers above the foundation piers .the commodore barry bridge is an example of this type of cantilever bridge 一种常见的方法构造钢桁架和预应力混凝土悬臂跨度是每一个悬臂抗衡预测相反的方向臂悬臂,形成一个平衡的悬臂。他们重视了坚实的基础,制约武器被称为锚武器/因此,在两个基础上建一座桥桥墩,有四个悬臂式武器,这两者之间跨越的障碍,和两个锚武器哪个延长距离的障碍,因为为更多的在平衡悬臂的支持力量的需要,桥梁上部结构往往表现为塔墩基础之上形成的准将巴里大桥是这种类型的例子悬臂桥 steel truss cantilever support loads by tension of the upper members and compression of the lower ones .commonly ,the structure distributes teh tension via teh anchor arms to the outermost supports ,while the compression is carried to the foundation beneath teh central towers .many truss cantilever bridges use pinned joints and are therefore statically determinate with no members carrying mixed loads 钢桁架悬臂由上层成员和下层的紧张压缩支持负载。通常,结构分布通过锚武器的最外层的支持紧张,而压缩抬到下方的中央塔的基础。桁架悬臂许多桥梁使用固定的关节,是静定,没有携带混合负载的成员,因此 prestressed concrete balanced cantilever bridges are often built using segmental construction .some steel arch bridges are built using pure cantilever spans from each sides,with neither falsework below nor temporary supporting towers and cables above ,these are then joined with a pin,usually after forcing the union point apart ,and when jacks are removed and the bridge decking is added the bridge becomes a truss arch bridge .such unsupported construction is only possible where appropriate rock is available to support the tension in teh upper chord of the span during construction ,usually limiting this method to the spanning of narrow canyons 预应力混凝土平衡悬臂桥梁往往建立使用段施工。一些钢拱桥是使用各方面的纯悬臂跨度既无假工作下面也临时支撑塔和电缆上面,这些都是再加入了一根针,通常在迫使工会点外,当插孔删除,并添加桥梁甲板桥成为桁架拱桥,这种不支持的建设,才可能在适当情况下的岩石可用于支持在施工期间的跨度弦上的张力,通常限制这狭隘的峡谷跨越方法 an arch bridge is a bridge with abutments at each end shaped as a curved arch .arch bridges work by transferring the weight of the bridge and its loads partially into a horizontal thrust restrained by the abutments at either side .a viaduct may be made from a series of arches ,although other more economical structures are typically used today 在拱桥桥台的桥梁,是一个在一个弧形拱状,每年年底。拱桥通过转移到由部分在两边的桥台水平推

土木工程专业英语原文及翻译

土木工程专业英语原文 及翻译 文档编制序号:[KKIDT-LLE0828-LLETD298-POI08]

08 级土木(1) 班课程考试试卷 考试科目专业英语 考试时间 学生姓名 所在院系土木学院 任课教师 徐州工程学院印制 Stability of Slopes Introduction Translational slips tend to occur where the adjacent stratum is at a relatively shallow depth below the surface of the slope:the failure surface tends to be plane and roughly parallel to the slips usually occur where the adjacent stratum is at greater depth,the failure surface consisting of curved and plane sections. In practice, limiting equilibrium methods are used in the analysis of slope stability. It is considered that failure is on the point of occurring along an assumed or a known failure surface.The shear strength required to maintain a condition of limiting equilibrium is compared with the available shear strength of the soil,giving the average factor of safety along the failure surface.The problem is considered in two dimensions,conditions of plane strain being assumed.It has been shown that a two-dimensional analysis gives a conservative result for a failure on a three-dimensional(dish-shaped) surface. Analysis for the Case of φu =0 This analysis, in terms of total stress,covers the case of a fully saturated clay under undrained conditions, . For the condition immediately after construction.Only moment equilibrium is considered in the analysis.In section, the potential failure surface is assumed to be a circular arc. A trial failure surface(centre O,radius r and length L a where F is the factor of safety with respect to shear strength.Equating moments about O:

科技英语翻译

第三单元 三种感情。单纯而极为强烈。支配了我的一生:对爱情的渴望。对知识的探索。以及对人类苦难忍无可忍的同情。这些激情。犹如飓风。吹得我忽东忽西。飘忽不定。越过茫茫的苦海。坠落绝望的边缘。我追求爱。原因有三。首先。是因为它使我心醉神迷——爱的魔力是如此的诱人。以至于我常常宁愿牺牲一切来换取哪怕片刻的愉悦。其次。是因为可以排遣孤寂——那种可怕的孤寂使身历其中的人胆战心惊。目及世界的尽头。直至冷酷肃杀的地狱深渊。最后。是因为在爱的结合中。我看到了古今圣贤以及诗人们所梦想的天堂的神秘缩影。这正是我想所追寻的。虽然它对人类生活来说也许过于美好。但最终我还是找到它了我曾怀着同样的激情去追求知识。我渴望了解人们的内心世界。渴望知道星星为什么发光。我还试图领悟毕达哥拉斯的学说的力量。凭借它。数字能掌控潮起潮落。我有所收获。但还不是很多。爱和知识引领我到天堂。但是对人类苦难的同情又常常把我拉回人世。人类痛苦的呼唤在我的心灵深处回响。嗷嗷待哺的儿童。惨遭蹂躏的受难者。儿女嫌弃的无助老人。以及满世界的孤独.贫困和痛苦。所有这些都是对人类理想生活的嘲讽。我希望能减缓人们的苦难。但却有心无力。我也因此受苦。这就是我的生活。我觉得不枉此生。倘若上帝赐我机会。我将欣然再活一次 Situated in the lower reaches of the Yangtze River and blessed with a mild climate ,fertile soil and numerous lakes and waterways across the region.Suzhou has enjoyed the reputation of ‘an area of fish and rice’ever since the Tang Dynasty (618A.D.-907A.D.).Historical records show that early in the Spring and Autumn Period(770B.C.-474B.C.)and the Warring States Period (475B.C.-221B.C.)the region was fairly advanced in fishery and farming.As a city of tourist attraction.Suzhou is dotted with bridges and waterways.Local residents’ houses always face the streets in the front and their backdoors are often built at water’s edge.Wherever waterways and streets cross.bridges are built to serve the purpose.The Map of PingjiangDistrict,a well-preserved city map carved on a stone plate in the Song Dynasty(960-1297).indicated that there were 304 bridges in those days. 第四单元 A.英译汉 如今。中同的经济繁荣已经成为一种得到充分证实的现象了。谁没有听说过这个泱泱大国令人眩目的经济发展速度(年增长率高达8%).颇具魅力的消费市场(拥有12亿消费者)和外国投资者的投资热情(仅去年一年外国直接投资就高达400亿美元)?中国的经济力量已经势不可挡。华盛顿一家智囊机构——布鲁金斯学会的尼古拉斯·拉迪说:“在过去20年中。世界上没有哪个国家的外贸发展速度有中国那么快。日本用了20多年时间才将其外贸总额翻了一番。而中国却翻了5倍。他们已经成为世界上劳动密集型产品的主要生产商。”不过。在这个令人眩目的中国发展故事中似乎缺少了一种什么东西。即中国跨国公司所扮演的角色。中国还没有一家大型公司在全球舞台上确立了自己的地位或品牌。但是。正如海尔公司所显示的那样。这种情况正在开始发生变化。经受了长达100年的贫穷.动乱以及长期笼罩在外国及其跨国公司的阴影下之后。中国的产业公司开始对世界产生影响了。 B.汉译英 Every struggle that the Chinese people fought during the 100 years from the mid-19th to the mid一20th century was for the sake of achieving independence of our country and liberation of our nation and putting an end to the history of national humiliation once and for a11.This great historic cause has already been accomplished.All endeavors by the Chinese people for the 100 years from the mid--20th to the mid-21st century are for the purpose of making our mother land strong,the people prosperous and the nation immensely rejuvenated.Our Party has led the entire Chinese people in carrying forward this historic cause for 50 years and made tremendous progress,and it will successfully attain the objective through hard work in the coming 50 years. 第五单元 翻译练习 A.英译汉硅谷犹如一块磁铁。把许许多多天资聪颖的工程师.科学家.企业家从世界各地聚集到这里。一起追求成名致富。并投身于技术革命的大潮。其影响及于人类。必将远远超过昔日划时代的欧洲文艺复兴和产业革命。随着互联网的急速普及。以及通过它所带来的无情的技术创新。信息时代真正来临了。它不但深刻地影响着我们的生活方式。而且正在改变我们的工作.贸易.思维以及彼此沟通的方式。值得注意的是。硅谷地区的专业人力资源。包括工程师.科学家和企业家。有将近一半来自亚洲。其中的精英是印度人和中国人。也有为数不少的人来自新加坡。除了知识上的挑战之外。新创企业为了延揽人才。还往往慷慨地给予员工们股票选购权。这一措施有力地激励员工们为公司尽心竭力。如果公司达到预期目标。员工们将与公司共享繁荣。许多人认为这是企业成功的基础。 B.汉译英 Suzhou boasts along history of garden construction.Private gardens made their appearances in the period of the Six Dynasties (around 1000A.D.).Towards the end of the Qing Dynasty (1636—1911),gardens of different dimensions being put on record numbered over 200.They fully demonstrate the ingenuity and creativity of the ancient Chinese craftsmen and are an invaluable heritage of the Chinese culture and classical architecture.Apart from being an important base of silk production , Suzhou is also a great producer of traditional handicrafts.Silk products of every description sell well in over 100 countries and regions and the varieties of locally produced handicrafts are too numerous to mention.Among those famous at home and abroad are Suzhou embroideries , mahogany carvings,jade—ware,sandalwood fans and woodcut prints of traditional Chinese New Year pictures,to name just a few. 第六单元 翻译练习 A.英译汉约150多年前。在英国的约克郡。有一个乡村教区的牧师。他有三位聪颖可爱的女儿。但是他却把希望完全寄托在唯一的继承人——儿子布兰韦尔身上。这个年轻人在艺术和文学上都有出众的天资。布兰韦尔的父亲和姐妹们都省吃俭用。帮他凑足盘缠。打点行装。送他上了伦敦皇家艺术学院。但是要指望他在艺术上有所成就。那他可就走错了门。不到几个星期。他就弄得身无分文。灰溜溜地回了家。然而家人并不就此罢休。他们又想方设法帮布兰韦尔弄到一份私人教师的活计。希望这份差事能够使他自由施展自己的文学才华。获取应有的功名。可这一次又失败了。几年来。无私的姐妹们压抑着自己的志向。应邀去学校任教或当家庭教师。以负担那日益债台高筑的弟弟。她们深信。总有一天。弟弟的天才会得到社会的承认。然而。接踵而来的失败使布兰韦尔一蹶不振。他染上了酗酒.吸毒的恶习。最后临死时仍与生前一样:一事无成。于是寄托在全家唯一男性身上的希望也随之破灭。而那三位默默无闻的姐妹。其命运又如何呢?在布兰韦尔生前最后几年。姐妹们自己集资出版了一本诗集(因为担心编辑们对女性存有偏见。她们用了假名)。但只卖出了两本。也许连布兰韦尔都在窃笑。然而姐妹们并不气馁。她们利用空余时间继续笔耕。深夜人静时。她们秉烛而书。倾吐她们幽禁的情怀。抒写自己最熟悉的一切。她们描写

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2.4 开启功能修复 解放桥中跨为开启跨,开启系统为施尔泽尔(Scherzer)式。这一系统通过电动机的动力输送,由齿轮组、动轮、齿条、弧形梁、平衡重密切的配合运动,使得末端齿轮轴的水平移动转化成扇形齿在固定齿梁上的滚动,这一随着开启角度而变化的转动轴,使桥梁在开启过程中,整个开启跨结构围绕转动轴处于受力的平衡状态,使桥梁有控制地徐徐向后仰起完成开启动作。桥梁开启后,两墩之间有42.7m的自由航道。 2.4 Repairing of the movable function The middle span of Liberation Bridge is a movable span whose movable system is Scherzer’s pattern. The opening system is driven by an electric motor. With the team motion of gear set, driving wheel, rack, curved beam and balance weight, horizontal motion of the gear shaft can be converted to be the roll of gear sector on fixed gear whose position varies with opening angle. Bridge structure is on the state of equilibrium with respect to the rotation axis when opening, which make it possible to open the bridge deck gradually in a controllable way. The width of free waterway is about 42.7m after bridge deck is opened. 解放桥开启系统严格按照原开启方式恢复,主要通过三步工作来实现。 1.通过实地考察、勘查与了解,明确解放桥的开启系统原理,完成开启系统的设计工作。 The opening system is repaired strictly according to the former opening pattern, and the repairing procedure can be divided into three steps as follows: 1. After field investigation and exploration, design the opening system with clearly comprehending the principle of opening system of Liberation Bridge. 2.安装调试 (1).车间内初安装调试 在车间内首先对每个传动部件进行初安装,调整好齿轮、支承件的位置与间隙,并在各个支承部件处加润滑脂,保证部件转动灵活;在车间内搭设辅助初调试平台,将所有上桥传动部件放在车间内的辅助初调试平台上,单侧活动跨的整体传动系统联接安装初调试,调整好各对齿轮间的位置与间隙,并在各个支承部件处加润滑脂,使得系统转动灵活,检查全部零部件并确认无遗漏情况。 2 Installation debugging (1) Initially installation debugging in workshop Every transmission part should be initially installed firstly in workshop. In this stage, the position of each gear and strutting piece should be adjusted and lubricating oil should be applied to each strutting piece to make sure their free rotation. Then all the transmission parts should be placed on the auxiliary initial debugging platform in

土木工程专业英语课文原文及对照翻译

土木工程专业英语课文原 文及对照翻译 Newly compiled on November 23, 2020

Civil Engineering Civil engineering, the oldest of the engineering specialties, is the planning, design, construction, and management of the built environment. This environment includes all structures built according to scientific principles, from irrigation and drainage systems to rocket-launching facilities. 土木工程学作为最老的工程技术学科,是指规划,设计,施工及对建筑环境的管理。此处的环境包括建筑符合科学规范的所有结构,从灌溉和排水系统到火箭发射设施。 Civil engineers build roads, bridges, tunnels, dams, harbors, power plants, water and sewage systems, hospitals, schools, mass transit, and other public facilities essential to modern society and large population concentrations. They also build privately owned facilities such as airports, railroads, pipelines, skyscrapers, and other large structures designed for industrial, commercial, or residential use. In addition, civil engineers plan, design, and build complete cities and towns, and more recently have been planning and designing space platforms to house self-contained communities. 土木工程师建造道路,桥梁,管道,大坝,海港,发电厂,给排水系统,医院,学校,公共交通和其他现代社会和大量人口集中地区的基础公共设施。他们也建造私有设施,比如飞机场,铁路,管线,摩天大楼,以及其他设计用作工业,商业和住宅途径的大型结构。此外,土木工程师还规划设计及建造完整的城市和乡镇,并且最近一直在规划设计容纳设施齐全的社区的空间平台。 The word civil derives from the Latin for citizen. In 1782, Englishman John Smeaton used the term to differentiate his nonmilitary engineering work from that of the military engineers who predominated at the time. Since then, the term civil engineering has often been used to refer to engineers who build public facilities, although the field is much broader 土木一词来源于拉丁文词“公民”。在1782年,英国人John Smeaton为了把他的非军事工程工作区别于当时占优势地位的军事工程师的工作而采用的名词。自从那时起,土木工程学被用于提及从事公共设施建设的工程师,尽管其包含的领域更为广阔。 Scope. Because it is so broad, civil engineering is subdivided into a number of technical specialties. Depending on the type of project, the skills of many kinds of civil engineer specialists may be needed. When a project begins, the site is surveyed and mapped by civil engineers who locate utility placement—water, sewer, and power lines. Geotechnical specialists perform soil experiments to determine if the earth can bear the weight of the project. Environmental specialists study the project’s impact on the local area: the potential for air and

土木工程专业英语正文课文翻译

第一课土木工程学 土木工程学作为最老的工程技术学科,是指规划,设计,施工及对建筑环境的管理。此处的环境包括建筑符合科学规范的所有结构,从灌溉和排水系统到火箭发射设施。 土木工程师建造道路,桥梁,管道,大坝,海港,发电厂,给排水系统,医院,学校,公共交通和其他现代社会和大量人口集中地区的基础公共设施。他们也建造私有设施,比如飞机场,铁路,管线,摩天大楼,以及其他设计用作工业,商业和住宅途径的大型结构。此外,土木工程师还规划设计及建造完整的城市和乡镇,并且最近一直在规划设计容纳设施齐全的社区的空间平台。 土木一词来源于拉丁文词“公民”。在1782年,英国人John Smeaton为了把他的非军事工程工作区别于当时占优势地位的军事工程师的工作而采用的名词。自从那时起,土木工程学被用于提及从事公共设施建设的工程师,尽管其包含的领域更为广阔。 领域。因为包含范围太广,土木工程学又被细分为大量的技术专业。不同类型的工程需要多种不同土木工程专业技术。一个项目开始的时候,土木工程师要对场地进行测绘,定位有用的布置,如地下水水位,下水道,和电力线。岩土工程专家则进行土力学试验以确定土壤能否承受工程荷载。环境工程专家研究工程对当地的影响,包括对空气和地下水的可能污染,对当地动植物生活的影响,以及如何让工程设计满足政府针对环境保护的需要。交通工程专家确定必需的不同种类设施以减轻由整个工程造成的对当地公路和其他交通网络的负担。同时,结构工程专家利用初步数据对工程作详细规划,设计和说明。从项目开始到结束,对这些土木工程专家的工作进行监督和调配的则是施工管理专家。根据其他专家所提供的信息,施工管理专家计算材料和人工的数量和花费,所有工作的进度表,订购工作所需要的材料和设备,雇佣承包商和分包商,还要做些额外的监督工作以确保工程能按时按质完成。 贯穿任何给定项目,土木工程师都需要大量使用计算机。计算机用于设计工程中使用的多数元件(即计算机辅助设计,或者CAD)并对其进行管理。计算机成为了现代土木工程师的必备品,因为它使得工程师能有效地掌控所需的大量数据从而确定建造一项工程的最佳方法。 结构工程学。在这一专业领域,土木工程师规划设计各种类型的结构,包括桥梁,大坝,发电厂,设备支撑,海面上的特殊结构,美国太空计划,发射塔,庞大的天文和无线电望远镜,以及许多其他种类的项目。结构工程师应用计算机确定一个结构必须承受的力:自重,风荷载和飓风荷载,建筑材料温度变化引起的胀缩,以及地震荷载。他们也需确定不同种材料如钢筋,混凝土,塑料,石头,沥青,砖,铝或其他建筑材料等的复合作用。 水利工程学。土木工程师在这一领域主要处理水的物理控制方面的种种问题。他们的项目用于帮助预防洪水灾害,提供城市用水和灌溉用水,管理控制河流和水流物,维护河滩及其他滨水设施。此外,他们设计和维护海港,运河与水闸,建造大型水利大坝与小型坝,以及各种类型的围堰,帮助设计海上结构并且确定结构的位置对航行影响。 岩土工程学。专业于这个领域的土木工程师对支撑结构并影响结构行为的土壤和岩石的特性进行分析。他们计算建筑和其他结构由于自重压力可能引起的沉降,并采取措施使之减少到最小。他们也需计算并确定如何加强斜坡和填充物的稳定性以及如何保护结构免受地震和地下水的影响。 环境工程学。在这一工程学分支中,土木工程师设计,建造并监视系统以提供安全的饮用水,同时预防和控制地表和地下水资源供给的污染。他们也设计,建造并监视工程以控制甚至消除对土地和空气的污染。

土木工程英文翻译

外文文献及译文 文献、资料题目:PROTECTION AGAINST HAZARDS 院(部):建筑工程学院 专业:土木工程 班级:土木081 姓名:孙继佳 学号:200811003192 指导教师:樊江 翻译日期:2012.5.4

3.1 PROTECTION AGAINST WA TER Whether thrust against and into a building by a flood, driven into the interior by a heavy rain, leaking from plumbing, storm surge, or seeping through the exterior enclosure, water can cause costly damage to a building. Consequently, designers should protect buildings and their contents against water damage. Protective measures may be divided into two classes: floodproofing and waterproofing.Floodproofing provides protection against flowing surface water, commonly caused by a river overflowing its banks. Waterproofing provides protection against penetration through the exterior enclosure of buildings of groundwater, rainwater,and melting snow. Buildings adjacent to large water bodies may also require protection from undermining due to erosion and impact from storm driven waves. 3.4.1Floodproo?ng A ?ood occurs when a river rises above an elevation,called ?ood stage,and is not Prevented by enclosures from causing damage beyond its banks.Buildings con- Structed in a ?ood plain,an area that can be inundated by a ?ood,should be Protected against a ?ood with a mean recurrence interval of 100 years.Maps Showing ?ood-hazard areas in the United States can be obtained from the Federal InsuranceAdministrator,DepartmentofHousingandUrbanDevelopment,who Administers the National Flood Insurance Program.Minimum criteria for?ood- proo?ng are given in National Flood Insurance Rules and Regulations(Federal Register, vol.41,no.207,Oct.26,1976). Major objectives of ?oodproo?ng are to protect fully building and contents from Damage from a l00-year ?ood,reduce losses from more devastating ?oods,and Lower ?ood insurance premiums.Floodproo?ng,however,would be unnecessary if Buildings were not constructed in ?ood prone areas.Building in ?ood prone areas Should be avoided unless the risk to life is acceptable and construction there can Be economically and socially justi?ed. Some sites in flood prone areas possess some ground high enough to avoid flood damage. If such sites must be used, buildings should be clustered on the high areas. Where such areas are not available, it may be feasible to build up an earth fill, with embankments protected against erosion by water, to raise structures above flood levels. Preferably, such structures should not have basements, because they would require costly protection against water pressure. An alternative to elevating a building on fill is raising it on stilts (columns in an unenclosed space). In that case, utilities and other services should be protected against damage from flood flows. The space at ground level between the stilts may be used for parking automobiles, if the risk of water damage to them is acceptable or if they will be removed before flood waters reach the site. Buildings that cannot be elevated above flood stage should be furnished with an impervious exterior. Windows should be above flood stage, and doors should seal tightly against their frames. Doors and other openings may also be protected with a flood shield, such as a wall. Openings in the wall for access to the building may be protected with a movable flood shield, which for normal conditions can be stored

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