同济大学土木工程本科毕业设计-框架结构设计翻译(译文)
土木工程毕业设计译文 原稿为Comparison of Seismic Performance of
汶川地震前后钢筋混凝土框架结构的抗震性能比较摘要：2008年发生在中国的汶川大地震导致了大量的人员伤亡和财产损失.对地震之前和现在的混凝土框架结构的脆弱点比较是为了从理论上减小未来的损失。
一种之前在地震中被损坏的典型钢筋混凝土框架结构通过非线性有限元发进行分析.用于这些钢筋混凝土框架结构的基于概率论的地震响应模型被建立起来用来对之前和现在的建筑物的安全等级进行评估。
从关于及时占有率，重大损失，和损毁预防等级的脆弱性曲线的比较和分析可以看出，相比地震之前的混凝土框架结构，现在的混凝土框架结构有更高的安全等级。
关键词：钢筋混凝土框架结构，地震安全性,脆弱性评估,汶川地震引言:发生在2008年的里氏7。
9级汶川大地震是中国在过去50年中发生的最具破坏力的地震之一。
根据中国国家地震局发布的汶川地震等级地图显示，其震中最大烈度高达10度。
这样强烈的地表运动带来的直接结果是大概23143000房屋被损毁,其中多达6525000倒塌，主要在断层带上。
很多钢筋混凝土框架结构的建筑都遭受了大面积的和严重的损坏.汶川地震之后，很多国内和国际的组织着手对这些震区的损毁建筑进行调查研究。
地震发生后，由广州建筑鉴定中心派出的观测队被派往震中地区调查这些土木建筑表现的一手资料。
双河超市建筑修建于2006年，它是这次地震中被归类为中度受损建筑中的典型范例.六层楼高的框架结构双河超市建筑的面貌如图一所示。
虽然建筑受损有限，但是建筑在很多梁，柱，以及梁柱节点上产生了大量的裂缝。
出现的最严重的的损坏出现在一楼到三楼的柱上（框架被砖墙填充）。
部分出现在二楼的裂缝沿着框架的东南方向延伸开来(如图1b所示）。
在这个位置上，柱子由于剪力的缘故产生连续的倾斜,混凝土产生剥落，然而调查队发现内部的框架梁很少发生损坏。
梁的损坏主要发生在楼梯间.如图1c所示。
框架结构的梁柱节点在地震中表现优良.建筑东南方向梁柱节点的损伤情况见图1d.双河超市建筑的安全检查报告显示建筑物在地震前的可靠性和表现不能满足抗震规范（2001)的要求。
土木工程结构设计专业毕业设计英语翻译
XXXXXXXXX学院学士学位毕业设计（论文）英语翻译课题名称英语翻译学号学生专业、年级所在院系指导教师选题时间目录1、第一篇 (3)2、第二篇 (6)3、第三篇 (9)Concrete, Reinforced Concrete, and PrestressedConcreteConcrete is a stone like material obtained by permitting a carefully proportioned mixture of cement, sand and gravel or other aggregate, and water to harden in forms of the shape and dimensions of the desired structure. The bulk of the material consists of fine and coarse aggregate. Cement and water interact chemically to bind the aggregate particles into a solid mass. Additional water, over and above that needed for this chemical reaction, is necessary to give the mixture workability that enables it to fill the forms and surround the embedded reinforcing steel prior to hardening. Concretes with a wide range of properties can be obtained by appropriates adjustment of the proportions of the constituent materials. Special cements, special aggregates, and special curing methods permit an even wider variety of properties to be obtained.These properties depend to a very substantial degree on the proportions of the mix, on the thoroughness with which the various constituents are intermixed, and on the conditions of humidity and temperature in which the mix is maintained from the moment it is placed in the forms of humidity and hardened. The process of controlling conditions after placement is known as curing. To protect against the unintentional production of substandard concrete, a high degree of skillful control and supervision is necessary throughout the process, from the proportioning by weight of the individual components, trough mixing and placing, until the completion of curing.The factors that make concrete a universal building material are so pronounced that it has been used, in more primitive kinds and ways than at present, for thousands of years, starting with lime mortars from 12,000 to 600 B.C. in Crete, Cyprus, Greece, and the Middle East. The facility with which , while plastic, it can be deposited and made to fill forms or molds of almost any practical shape is one of these factors. Its high fire and weather resistance are evident advantages. Most of the constituent materials, with the exception of cement and additives, are usually available at low cost locally or at small distances from the construction site. Its compressive strength, like that of natural stones, is high, which makes it suitable for members primarily subject to compression, such as columns and arches. On the other hand, again as in natural stones, it is a relatively brittle material whose tensile strength is small compared with its compressive strength. This prevents its economical use in structural members that ate subject to tension either entirely or over part of their cross sections.To offset this limitation, it was found possible, in the second half of thenineteenth century, to use steel with its high tensile strength to reinforce concrete, chiefly in those places where its low tensile strength would limit the carrying capacity of the member. The reinforcement, usually round steel rods with appropriate surface deformations to provide interlocking, is places in the forms in advance of the concrete. When completely surrounded by the hardened concrete mass, it forms an integral part of the member. The resulting combination of two materials, known as reinforced concrete, combines many of the advantages of each: the relatively low cost , good weather and fire resistance, good compressive strength, and excellent formability of concrete and the high tensile strength and much greater ductility and toughness of steel. It is this combination that allows the almost unlimited range of uses and possibilities of reinforced concrete in the construction of buildings, bridges, dams, tanks, reservoirs, and a host of other structures.In more recent times, it has been found possible to produce steels, at relatively low cost, whose yield strength is 3 to 4 times and more that of ordinary reinforcing steels. Likewise, it is possible to produce concrete 4 to 5 times as strong in compression as the more ordinary concrete. These high-strength materials offer many advantages, including smaller member cross sections, reduced dead load, and longer spans. However, there are limits to the strengths of the constituent materials beyond which certain problems arise. To be sure, the strength of such a member would increase roughly in proportion to those of the materials. However, the high strains that result from the high stresses that would otherwise be permissible would lead to large deformations and consequently large deflections of such member under ordinary loading conditions. Equally important, the large strains in such high-strength reinforcing steel would induce large cracks in the surrounding low tensile strength concrete, cracks that would not only be unsightly but that could significantly reduce the durability of the structure. This limits the useful yield strength of high-strength reinforcing steel to 80 ksi according to many codes and specifications; 60 ksi steel is most commonly used.A special way has been found, however, to use steels and concrete of very high strength in combination. This type of construction is known as prestressed concrete. The steel, in the form of wires, strands, or bars, is embedded in the concrete under high tension that is held in equilibrium by compressive stresses in the concrete after hardening, Because of this precompression, the concrete in a flexural member will crack on the tension side at a much larger load than when not so precompressed. Prestressing greatly reduces both the deflections and the tensile cracks at ordinaryloads in such structures, and thereby enables these high-strength materials to be used effectively. Prestressed concrete has extended, to a very significant extent, the range of spans of structural concrete and the types of structures for which it is suited.混凝土，钢筋混凝土和预应力混凝土混凝土是一种经过水泥，沙子和砂砾或其他材料聚合得到经过细致配比的混合物，在液体变硬使材料石化后可以得到理想的形状和结构尺寸。
同济大学土木工程本科毕业设计译文正文-0530修改-罗兆奇
┊┊┊┊┊┊┊┊┊┊┊┊┊装┊┊┊┊┊订┊┊┊┊┊线┊┊┊┊┊┊┊┊迪尔伯恩七南大厦结构优化设计William F. Baker, Lawrence C. Novak, Robert C. Sinn, John R. Viise【摘要】拟于芝加哥建造的迪尔伯恩七南大厦（7 South Dearborn tower），高度将达到2000英尺（609米），建成之日将会成为世界上最高的建筑，同时也会是世界上最为细长的高楼之一（高宽比接近8.5：1）。
这座多用途建筑将把底层用于商业，较低层用于办公，稍高层用作住宅，而通讯设备（包括数字信号广播）将占据最高的几个楼层。
为这座大楼设计的创新性抗侧力体系主要由一个钢筋混凝土核心筒构成，同时为连接核心筒与结构下半部的周边钢柱，在设备层设置了钢结构外伸支架。
对塔楼抗侧力系统的结构经济性分析是整个项目可行性研究的必备要素。
基于结构分析与风洞试验结果，该建筑对风荷载的响应（挠度与加速度）是确定的。
对于高层建筑而言，抗侧力系统构件的尺寸，主要是由结构适用性功能要求控制，而并非是强度。
为了更经济地建成该建筑，我们谨慎地在众多选择中确定构件尺寸并有效地分配结构材料，以确定花销最少的结构方案。
本文总结了七南大厦的结构体系，并给出了优化策略，可在给定合并构件约束的挠度或周期控制要求下确定最小成本的解决方案。
┊┊┊┊┊┊┊┊┊┊┊┊┊装┊┊┊┊┊订┊┊┊┊┊线┊┊┊┊┊┊┊┊迪尔伯恩七南大厦简介迪尔伯恩七南大厦将会成为芝加哥地平线上激动人心的新地标。
建成之日，该塔楼能够满足由“高层建筑及城市人居委员会”为排列世界上最高的几座建筑物设定的全部四项指标（见图1、2）。
这座大楼坐落于迪尔伯恩与麦迪逊大街的东南角，将会在那占据一个相对小而方的区域，每边大约182英尺（55.5米）。
塔楼的地上100层与2层地下室将容纳大约190万平方英尺（176200平方米）的商业、办公、停车场、住宅以及通讯设备。
同济大学土木工程本科毕业设计-框架结构设计计算书终稿
指导教师
【设计总说明】
1 建筑设计总说明 1.1 工程概况 本建筑是上海某生物技术公司办公楼，地处上海市浦东新区。经上级主管部门和城建部门批准，该公司拟建 造一栋总建筑面积为 1800 m2 的三层现浇钢筋混凝土框架结构办公楼。 1.2 设计资料 ⑴ ⑵ ⑶ ⑷ ⑸ ⑹ 本建筑设计使用年限：50 年。 建筑结构重要性等级：二级。抗震设防烈度 7 度，抗震设防类别为丙类，设计地震分组为第一组建筑 场地四类。 楼面和屋面活荷载标准值为 2.0kN/m2。 风荷载设计参数：基本风压为 0.55kN/m2，地面粗糙度类别为 C。 雪荷载设计参数：基本雪压为 0.20kN/m2。 工程地质资料 地 下 水 位 在 地 表 以 下 0.55m 处 。 按工程地质勘察报告，场地地层特性为： 第①层素 填 土 ： 平 均 厚 1.6 m。 第②层粉质粘土：褐黄色，平均层厚 2.50m,压缩系数 a＝0.34MPa-1，中压缩性，土质相对较好，容许 承载力 f ＝95kN / m2。 第③层 淤 泥 质 粉 质 粘 土 : 灰 色 ， 平 均 层 厚 6.30m ， 流 塑 ， 高 压 缩 性 ， 容 许 承 载 力 f ＝ 75kN/m2。 第④层 淤 泥 质 粘 土 ： 灰 色 ， 平 均 层 厚 3.96m ， 流 塑 ， 高 压 缩 性 ， 容 许 承 载 力 f ＝ 65kN/m2。 第⑤层 淤 泥 质 粉 质 粘 土 ：灰 色 ，平 均 层 厚 3.30m ，流 塑 ，高 压 缩 性 ，容 许 承 载 力 f ＝ 60kN/m2。 第⑥层 粉 质 粘 土 ： 灰 色 ， 平 均 层 厚 8.30m ， 软 塑 ， 高 偏 中 压 缩 性 ， 容 许 承 载 力 f ＝ 75kN/m2。 1.3 平面设计 1.3.1 总平面设计 从总平面布置的基本原则考虑，本建筑采用“一”字体型。主入口设在南面并靠近西面，为了满足防火、紧 急时刻人员疏散要求，本建筑在东面设一侧门。 1.3.2 主要房间设计
同济大学土木工程本科毕业设计译文原文-罗兆奇
Structural Optimization of 2000’ Tall 7 South Dearborn BuildingWilliam F. Baker, Lawrence C. Novak, Robert C. Sinn, John R. Viise AbstractThe 2000 foot (609 meter) tall 7 South Dearborn tower proposed for Chicago, will be, at time of completion, the tallest building in the world and also one of the most slender with an overall aspect ratio of approximately 8.5 to 1. The 110-story building is a multi-use project with retail comprising the ground floor, offices in the lower section, residential comprising the upper sections, and telecommunications (including digital television broadcasting) occupying the highest floors. The innovative lateral load resisting system developed for the tower consists of a reinforced concrete core wall, with structural steel outriggers at the mechanical floors, connecting the core to structural steel perimeter columns in the lower half of the building.An overall structural economy of the lateral system for the tower is a requirement for the feasibility of the project. Based on structural analysis and wind tunnel testing, the building responses to wind loadings (deflections and accelerations) were determined. The sizing of the members of the lateral system for high-rise buildings is often controlled primarily by serviceability requirements rather than strength. In order to achieve an economical building, it is prudent that these elements are appropriately sized and the structural materials are efficiently distributed among the various components to result in a least cost solution. This paper summarizes the structural system for the 7 South Dearborn tower and presents the optimization techniques utilized to determine a least cost solution for a given deflection or period incorporating member constraints.Introduction to the 7 South Dearborn BuildingThe 7 South Dearborn Building will be a dramatic addition to the skyline of Chicago. When completed, the tower will satisfy all four criteria established by the Council on Tall Buildings and Urban Habitat in determining their rankings of the world’s tallest building (Fig. 1 and 2).Located at the southeast corner of Dearborn and Madison Streets, the building will have a relatively small, square foot-print, 182 feet (55.5 meters) per side. The tower’s 100 stories and two basements will accommodate approximately 1.9 million square feet (176,200 meters2) of retail, office, parking, residential, and telecommunication facilities. The aluminum and stainless steel clad building has a futuristic look resembling a lightning bolt suspended in time. Various functions will be separated into six distinct sections. The lower 11 floors of parking and retail (75,000 ft.2) along with five floors of office will be separated from the remaining office space (32 floors and 765,000 ft2 total) by a plan setback. After an additional setback in the middle of the remaining office floors, another setback separates office space from residential floors (360 units, 476,000 ft2). The 40 floors of residential are then subdivided into approximately two equalsections by notched reveals of the building core wall. The top 13 floors of telecommunication facilities and two 450 foot tall antennae are separated from the residential block by a final notched reveal (Fig. 1 and 2).7 South Dearborn will be the first mixed-use building specifically designed to accommodate digital television broadcasting. The building will also include the highest residential units in the world, surpassing The John Hancock Building. Additionally, cantilevered framing at the upper floors will produce residential units with no exterior columns and dramatic 11 foot (floor to ceiling) uninterrupted views of the city.Structural System DescriptionFoundations7 South Dearborn will be constructed on the site of an existing structure. The foundation system is a caisson supported mat and will utilize straight-shaft caissons socketed into bedrock (Fig. 3).Superstructure / “Stayed Mast Structure”7 South Dearborn’s lateral system has been termed a “stayed-mast” system (Fig. 3). From the foundations to the top of the parking levels a perimeter reinforced concrete wall, stiffens the main tower core wall. The primary reinforced concrete core wall (“mast”), up to 4 feet (1200 mm) thick, and 66 feet (20 meters) square, utilizes high-strength concrete up to 12,000 psi (100 MPa cube strength). The outer concrete wall at the parking levels effectively moves the base of the building up, from a structural and behavioral point of view. From the top of the parking levels to the top of the office floors, exterior steel column bundles (“stays”) engaged by multi-story outrigger trusses stiffen the concrete core. These outrigger trusses occur only at the mechanical levels, which limits their impact on the architecture. Additionally, the bundled steel column spacing is kept to a least 30 feet (9.1 meters) on center in order to minimize exterior obstructions. From the bottom of the residential and telecommunication facility floors to the roof, the core alone resists imposed vertical and lateral loads. Torsional stiffness is derived through the uninterrupted core walls and perimeter concrete tube in the parking levels.Floor Framing SystemsThe lower retail and ground levels utilize a two-way flat slab system while the parking levels utilize a composite steel beam and one-way slab system. At the office floors, composite floor framing is utilized. Composite steel beams spanning up to 58 feet (17.6 meters) or composite floor trusses will be used. A 2 ½” (63 mm) lightweight topping slab over 3” (75mm) composite steel deck will provide the required hourly fire rating. For residential and telecommunication facility floors, cantilevered post-tensioned framing is utilized. Conventional reinforced concrete 4 5/8” (117 mm) one-way slabs span to post-tensioned beams which taper from 36” to 9” (914 mm to 228 mm) deepand cantilever out from the reinforced concrete core wall. The cantilevered construction at these levels is extremely beneficial in that it allows for simple construction (no exterior columns) while stabilizing the core by keeping all gravity loads in the core at the upper levels. Additionally, cantilevered floor plates eliminate any problems due to differential shortening of vertical elements at the upper levels.Wind Engineering Due to the slender nature of the building, occupant perception of motion at the upper floors is a major concern in the development of the lateral system. The tower’s translational periods, T x and T y =9 seconds, are separated well from the building’s torsional third mode of 2.5 seconds. The criteria to limit motion perception for residential occupancy is quite strict: between 10 and 15 mg translational acceleration based on a 10-year return period wind event.During the conceptual phase of the project, two wind tunnel tests were completed at the RWDI laboratories in Guelph, Ontario, Canada. Through these tests, the sensitivity of building accelerations due to mass and stiffness changes was established. The tower design employs various aerodynamic solutions to reduce the impact of wind loads. The basic square cross-section of the tower in plan avoids vortex shedding resonance at normal design wind speeds. Additionally, the use of setbacks, notched reveals, and rounded building corners disrupts organized vortex shedding behavior. For this optimized shape, it was determined that building accelerations for the slender 7 South Dearborn Tower, over the range of design wind speeds, were best described by the following relationship:a ξ5.037.137.0M k G ∝Where,a = peak acceleration K = generalized stiffness M G = generalized mass = m i *d i 2m i = mass at floor i d i = normalized modal shape at floor i What is apparent from this relationship is that increasing the generalized stiffness (or shortening the period) of the building actually has a slightly detrimental effect when considering building accelerations, whereas increasing generalized mass produces a significantly more beneficial effect. These results served as a basis for decisions to utilize concrete framing at the top portion of the tower, the decision to limit the use of lightweight concrete, and the decision not to decrease the thickness of the concrete core wall in the upper stories, but to instead decrease its concrete strength (thereby reducing its stiffness). The large, massive, uninterrupted core walls also form a ξ= damping ratiohighly stiff torsional system limiting peak torsional accelerations at the upper occupied floor levels to well within accepted criteria.OptimizationTheoretical ApproachSeveral factors control the structural design of a high-rise building including: strength, stiffness (drift), and serviceability (motion perception and accelerations). As buildings become taller and more slender, strength becomes less of a controlling concern. In order to control drift, lateral stiffness is a fundamental aspect of the design. In order to control accelerations, the natural period and generalized mass of the building are important aspects. The stiffness and natural period of a building are inherent properties of a structure and are controlled by the type of system, materials, and individual element sizes. In order to achieve the most economical structure, the structural materials must be efficiently distributed among the individual components. Historically an engineer increased a building’s stiffness by a) increasing the size of all of the individual elements proportionally, b) trial and error or c) approximate hand methods. The state-of-the-art in structural optimization for tall buildings now involves energy based methods to determine the optimal distribution of structural materials to obtain the least material cost solution for a target deflection or target natural period.Application of Optimization Method – Deflection CriteriaTo produce the least material cost solution to the problem of resisting a prescribed wind load without exceeding a deflection criterion (such as tip deflection); the following basic concepts are assumed:1.The building structural response for wind loads is linearly elastic.2.The total cost of the structure is the sum of the individual component costs.3.The cost of an individual component is the volume of material in the componenttimes a costing factor.4.As individual members change size, forces in the members do not change (i.e.: thestructure is statically determinate). This criterion is not as restrictive as it appears.All tall buildings are inherently cantilevers from the ground, such that at any floor the overturning moment and shears are known (Fig. 4).5.As an individual member changes in cross-sectional area, the other membersection properties (shear area, moment of interia, torsional constant) change in constant proportion to the change in axial area. This criterion is reasonably accurate, as long as the members do not change drastically in depth.6.Member forces are known due to both a) the prescribed loading and b) a unit loadapplied at the location at which the deflection criterion is tested.7.The analysis model is composed of beam or truss elements.Based on the above assumptions, the following equation can be derived:Cost / Material Optimization (Including Constraints and Grouping)At first glance, the optimization technique described above appears to have three major problems associated with real world application to building structures.Problem 1: The resulting approach results in each and every member possibly being different in a structure. This is not realistic or practical for actual design, which recognize the benefit of standardizing member sizes, strengths, and proportions.Solution to Problem 1: By grouping members usable results can be achieved (for example it may be desirable to have all spandrel beams at a floor be the same size, or to group walls with the same thickness). Grouping can be accomplished by treating several related members (with the same axial area) in the optimization phase as a single member.Problem 2: The optimization approach may result in an element size smaller or larger than deemed permissible by the engineer based on gravity or strength considerations alone. Alternatively, the solution may suggest a structural steel corner column in a building to be larger than that which can be manufactured or shipped (Fig. 5). Solution to Problem 2: By constraining certain member groups to either a maximum and/or minimum size, the engineer can control the range of possible solutions. The engineer can set the constraint criteria on element sizes such that the optimal results also satisfy the project requirements. Using this technique the engineer can still optimize the structure for deflection while maintaining strength or other constraints on member sizes.Problem 3: The structure can only be optimized for a singe deflection criterion at a time. Most structures have multiple deflection criteria. For example, when you optimize for east-west winds only, the lateral load system resisting north-south winds may be reduced to zero by optimization.Solution to Problem 3: By strategically utilizing a combination of the solutions to Problems 1 and 2 above, the engineer can also resolve Problem 3. For example when optimizing for east-west winds, the lateral load system resisting north-south winds can be constrained to their minimum size. For a square doubly symmetric building with equal wind loads in each direction, the lateral load resisting systems in each direction can be grouped together, thereby requiring only an optimization in a single direction. Real world structures have multiple deflection and strength criteria, (reference papers by Chun-Man Chan of the Hong Kong University of Science & Technology), however; significant information can be derived by optimizing for a single critical deflection criterion. Hence, more complex optimization would not generally be required.Optimization for Period and Generalized MassThe motion perception of a high-rise building is often affected by the period of the structure. Based on a similar approach as described above, an equation can be derived which results in the least cost of structural materials for a target natural period and generalized mass. The approach is similar to loading the building with the mode shape to see how the structure responds.Application to 7 South Dearborn BuildingWith the complex interaction between the concrete core wall and the structural steel outriggers and perimeter columns, the contribution of each to the total deflection is not straightforward. The optimization method above reduced the time and complexity to reach a reasonable structural solution to this complex problem. By reducing the cost estimate of the structure during the concept design phase, the feasibility of the project was improved.Conclusion7 South Dearborn represents a major advancement in the evolution of super-tall buildings. This slender tower breaks through several barriers that have limited buildings in the 100+ story range. The tower profile is unique and unprecedented but is soundly based on the integration of tall building technological requirements and the function of the enclosed space. The architectural integration and interpretation of aerodynamic and structural requirements has resulted in an economical and striking aesthetic design that will likely become the icon for Chicago. From the point of view of the development community, this building with its “stayed-mast” structural system also represents a breakthrough as the tower is able to soar to unmatched heights with much smaller floor plates for the lower floors than were utilized on earlier super-tall towers. These smaller floor plates are highly marketable and attractive to a larger segment of the office rental community in comparison to the very large floor plates of some of the preceding 100+ story buildings. Innovative optimization techniques applied early in the design process can now allow for economical, least cost structures for super-tall buildings in a variety of wind environments.ReferencesBaker, W.F., 1992Structural Engineering International, Published by IABSE, May 1992, pp. 99-102. About the AuthorsWilliam F. Baker is the Structural Engineering Partner at Skidmore, Owings & Merrill LLP, Chicago ILRobert C. Sinn is an Associate Partner at Skidmore, Owings & Merrill LLP, Chicago Lawrence C. Novak and John R. Viise are Associates at Skidmore, Owings & Merrill LLP, Chicago。
土木工程毕业设计中英文翻译.doc
附录：中英文翻译英文部分：LOADSLoads that act on structures are usually classified as dead loads or live loads.Dead loads are fixed in location and constant in magnitude throughout the life of the ually the self-weight of a structure is the most important part of the structure and the unit weight of the material.Concrete density varies from about 90 to 120 pcf (14 to 19 2KN/m)for lightweight concrete,and is about 145 pcf (23 2KN/m)for normal concrete.In calculating the dead load of structural concrete,usually a 5 pcf (1 2KN/m)increment is included with the weight of the concrete to account for the presence of the reinforcement.Live loads are loads such as occupancy,snow,wind,or traffic loads,or seismic forces.They may be either fully or partially in place,or not present at all.They may also change in location.Althought it is the responsibility of the engineer to calculate dead loads,live loads are usually specified by local,regional,or national codes and specifications.Typical sources are the publications of the American National Standards Institute,the American Association of State Highway and Transportation Officials and,for wind loads,the recommendations of the ASCE Task Committee on Wind Forces.Specified live the loads usually include some allowance for overload,and may include measures such as posting of maximum loads will not be exceeded.It is oftern important to distinguish between the specified load,and what is termed the characteristic load,that is,the load that actually is in effect under normal conditions of service,which may be significantly less.In estimating the long-term deflection of a structure,for example,it is the characteristic load that is important,not the specified load.The sum of the calculated dead load and the specified live load is called the service load,because this is the maximum load which may reasonably be expected to act during the service resisting is a multiple of the service load.StrengthThe strength of a structure depends on the strength of the materials from which it is made.Minimum material strengths are specified in certain standardized ways.The properties of concrete and its components,the methods of mixing,placing,and curing to obtain the required quality,and the methods for testing,are specified by the American Concrete Insititue(ACI).Included by refrence in the same documentare standards of the American Society for Testing Materials(ASTM)pertaining to reinforcing and prestressing steels and concrete.Strength also depends on the care with which the structure is built.Member sizes may differ from specified dimensions,reinforcement may be out of position,or poor placement of concrete may result in voids.An important part of the job of the ergineer is to provide proper supervision of construction.Slighting of this responsibility has had disastrous consequences in more than one instance.Structural SafetySafety requires that the strength of a structure be adequate for all loads that may conceivably act on it.If strength could be predicted accurately and if loads were known with equal certainty,then safely could be assured by providing strength just barely in excess of the requirements of the loads.But there are many sources of uncertainty in the estimation of loads as well as in analysis,design,and construction.These uncertainties require a safety margin.In recent years engineers have come to realize that the matter of structural safety is probabilistic in nature,and the safety provisions of many current specifications reflect this view.Separate consideration is given to loads and strength.Load factors,larger than unity,are applied to the calculated dead loads and estimated or specified service live loads,to obtain factorde loads that the member must just be capable of sustaining at incipient failure.Load factors pertaining to different types of loads vary,depending on the degree of uncertainty associated with loads of various types,and with the likelihood of simultaneous occurrence of different loads.Early in the development of prestressed concrete,the goal of prestressing was the complete elimination of concrete ternsile stress at service loads.The concept was that of an entirely new,homogeneous material that woukd remain uncracked and respond elastically up to the maximum anticipated loading.This kind of design,where the limiting tensile stressing,while an alternative approach,in which a certain amount of tensile amount of tensile stress is permitted in the concrete at full service load,is called partial prestressing.There are cases in which it is necessary to avoid all risk of cracking and in which full prestressing is required.Such cases include tanks or reservious where leaks must be avoided,submerged structures or those subject to a highly corrosive envionment where maximum protection of reinforcement must be insured,and structures subject to high frequency repetition of load where faatigue of the reinforcement may be a consideration.However,there are many cses where substantially improved performance,reduced cost,or both may be obtained through the use of a lesser amount of prestress.Full predtressed beams may exhibit an undesirable amount of upward camber because of the eccentric prestressing force,a displacement that is only partially counteracted by the gravity loads producing downward deflection.This tendency is aggrabated by creep in the concrete,which magnigies the upward displacement due to the prestress force,but has little influence on the should heavily prestressed members be overloaded and fail,they may do so in a brittle way,rather than gradually as do beams with a smaller amount of prestress.This is important from the point of view of safety,because suddenfailure without warning is dangeroud,and gives no opportunity for corrective measures to be taken.Furthermore,experience indicates that in many cases improved economy results from the use of a combination of unstressed bar steel and high strength prestressed steel tendons.While tensile stress and possible cracking may be allowed at full service load,it is also recognized that such full service load may be infrequently applied.The typical,or characteristic,load acting is likely to be the dead load plus a small fraction of the specified live load.Thus a partially predtressed beam may not be subject to tensile stress under the usual conditions of loading.Cracks may from occasionally,when the maximum load is applied,but these will close completely when that load is removed.They may be no more objectionable in prestressed structures than in ordinary reinforced.They may be no more objectionable in prestressed structures than in ordinary reinforced concrete,in which flexural cracks always form.They may be considered a small price for the improvements in performance and economy that are obtained.It has been observed that reinforced concrete is but a special case of prestressed concrete in which the prestressing force is zero.The behavior of reinforced and prestressed concrete beams,as the failure load is approached,is essentially the same.The Joint European Committee on Concrete establishes threee classes of prestressed beams.Class 1:Fully prestressed,in which no tensile stress is allowed in the concrete at service load.Class 2:Partially prestressed, in which occasional temporary cracking is permitted under infrequent high loads.Class 3:Partially prestressed,in which there may be permanent cracks provided that their width is suitably limited.The choise of a suitable amount of prestress is governed by a variety of factors.These include thenature of the loading (for exmaple,highway or railroad bridged,storage,ect.),the ratio of live to dead load,the frequency of occurrence of loading may be reversed,such as in transmission poles,a high uniform prestress would result ultimate strength and in brittle failure.In such a case,partial prestressing provides the only satifactory solution.The advantages of partial prestressing are important.A smaller prestress force will be required,permitting reduction in the number of tendons and anchorages.The necessary flexural strength may be provided in such cases either by a combination of prestressed tendons and non-prestressed reinforcing bars,or by an adequate number of high-tensile tendons prestredded to level lower than the prestressing force is less,the size of the bottom flange,which is requied mainly to resist the compression when a beam is in the unloaded stage,can be reduced or eliminated altogether.This leads in turn to significant simplification and cost reduction in the construction of forms,as well as resulting in structures that are mor pleasing esthetically.Furthermore,by relaxing the requirement for low service load tension in the concrete,a significant improvement can be made in the deflection characteristics of a beam.Troublesome upward camber of the member in the unloaded stage fan be avoeded,and the prestress force selected primarily to produce the desired deflection for a particular loading condition.The behavior of partially prestressed beamsm,should they be overloaded to failure,is apt to be superior to that of fully prestressed beams,because the improved ductility provides ample warning of distress.英译汉：荷 载作用在结构上的荷载通常分为恒载或活载。
框架结构设计外文翻译
南京理工大学紫金学院毕业设计(论文)外文资料翻译系：机械工程系专业：土木工程姓名：袁洲学号： 050105140 外文出处：Design of prestressed(用外文写)concrete structures 附件： 1.外文资料翻译译文；2.外文原文。
附件1：外文资料翻译译文8-2简支梁布局一个简单的预应力混凝土梁由两个危险截面控制：最大弯矩截面和端截面。
这两部分设计好之后，中间截面一定要单独检查，必要时其他部位也要单独调查。
最大弯矩截面在以下两种荷载阶段为控制情况，即传递时梁受最小弯矩M G的初始阶段和最大设计弯矩M T时的工作荷载阶段。
而端截面则由抗剪强度、支承垫板、锚头间距和千斤顶净空所需要的面积来决定。
所有的中间截面是由一个或多个上述要求，根它们与上述两种危险截面的距离来控制。
对于后张构件的一种常见的布置方式是在最大弯矩截面采用诸如I形或T形的截面，而在接近梁端处逐渐过渡到简单的矩形截面。
这就是人们通常所说的后张构件的端块。
对于用长线法生产的先张构件，为了便于生产，全部只用一种等截面，其截面形状则可以为I形、双T形或空心的。
在第5 、 6 和7章节中已经阐明了个别截面的设计，下面论述简支梁钢索的总布置。
梁的布置可以用变化混凝土和钢筋的办法来调整。
混凝土的截面在高度、宽度、形状和梁底面或者顶面的曲率方面都可以有变化。
而钢筋只在面积方面有所变化，不过在相对于混凝土重心轴线的位置方面却多半可以有变化。
通过调整这些变化因素，布置方案可能有许多组合，以适应不同的荷载情况。
这一点是与钢筋混凝土梁是完全不同的，在钢筋混凝土梁的通常布置中，不是一个统一的矩形截面便是一个统一的T形，而钢筋的位置总是布置得尽量靠底面纤维。
首先考虑先张梁，如图 8-7，这里最好采用直线钢索，因为它们在两个台座之间加力比较容易。
我们先从图（a）的等截面直梁的直线钢索开始讨论。
这样的布置都很简单，但这样一来，就不是很经济的设计了，因为跨中和梁端的要求会产生冲突。
土木工程--毕业设计外文翻译(原文+翻译)
毕业设计（论文）外文翻译题目西北物流中心2号楼设计专业土木工程班级土木074学生指导教师二零一零年Low-coherence deformation sensors for themonitoring of civil-engineering structuresD. Inaudi a, A. Elamari b, L. Pflug a, N. Gisin b, J. Breguet b, S. Vurpillot a “IMAC, Laboratory of Stress Analysis, Swiss Federal Institute of Technology, CH-1015 Lausanne, Switzerland ‘GAP, Group of Applied Physics -Optical Seciion, Geneva University CH-1205 Geneva, SwitzerlandRcccivcd 25 January 1993; in revised form 8 March 1994; accepted 25 March 1994 AbstractAn optical-fiber deformation sensor with a resolution of 10 pm and an operational range of 60 mm has been realized. The system is based on low-coherence interferometry instandard single-mode telecommunication fibers. It allows the monitoring of large structures over several months without noticeable drift. No continuous measurement is needed and the system is insensitive to variations of the fiber losses. This technique has been applied to the monitoring of a 20 m X5 m X0.5 m, 120 ton concrete slab over six months. It is possible to measure the shrinkage of concrete and its elastic coefficient during pre-straining, giving reproducible results in good agreement with theoretical calculations and measurements performed on small concrete samples. This paper describes the optical arrangement and the procedures used to install optical fibers in concrete.Keywor&: Ikformation sensors; Civil-engineering structures1. IntroductionBoth the security of civil-engineering works and the law require a periodic monitoring of structures. The methods used for this purpose, such as triangulation, water levels or vibrating strings, are often of tedious application and require one or many specialized operators. This complexity and the resulting costs limit the frequency of the measurements. Furthermore, the spatial resolution is often poor and the observation is usually restricted to the surface of the object. There is thus a real demand for a tool allowing an internal, automatic and permanent monitoring of structures with high accuracy and stability over periods typically of the order of 100 years for bridges. In this framework, fiber-optic smart structures (i.e., structures with self-testing capabilities) are gaining in importance in many fields including aeronautics and composite material monitoring. This technology can be applied in civilengineering and in particular for the short- and long-time observation of large structures such as bridges, tall building frames, dams, tunnels, roads, airport runways, domes, pre-stressing and anchorage cables. The monitoring of such structures requires the development of a measuring technique with high accuracy,stability and reliability over long periods. It has to beindependent of variations in the fiber losses and adapted to the adverse environment of a building site. To reduce the cost of the instrumentation, it is furthermore desirable to use the same portable reading unit for the monitoring of multiple structures. We describe here asystem based on low-coherence interferometry responding to all these requirements.2. Experimental arrangementThe measuring technique relies on an array of standard telecommunication optical fibers in mechanical contact with concrete. Any deformation of the host structure results jn a change in the optical length of he fibers. Each sensor line consists of two single-mode ibers: one measurement fiber in mechanical contact with the structure (glued or cemented) and a reference iber placed loose near the first one (in a pipe) in order to be at the same temperature. Since the measurement technique monitors the length difference beween these two fibers, only the mechanical deformation will have an effect on the results while all other perurbations, such as thermally induced changes in the refractive index of the fibers,will affect the two in an identical way and cancel each another out. To measure the optical path difference between the two fibers, a low-coherence double interferometer in tandem configuration has been used (Fig. 1) [l]. The source is an LED (light-emitting diode) working around 1.3 pm with a coherence length L, of 30 pm and a rated power of 200 pW. The radiation is launched into a single-mode fiber and then directed toward the measurement and the reference fibers by means of a 50:50 single-mode directional coupler. At the ends of the fibers two mirrors reflect the light back to the coupler, where the beams arc recombined with a relative delay due to the length difference AL, between the fibers, and then directed towards the second (reference) interferometer. The reference interferometer is of Michelson type with one of the arms ended by a mobile mirror mounted on a micromctric displacement table with a resolution of 0.1 pm and an operating range of 50 mm. It allows the introduction of an exactly known path difFcrence AL, between its two arms. This fiber interferometer is portable and needs no optical adjustment after transportation. It has been developed by the GAP with the support of the Swiss PTT for optical cable testing [2].The intensity at the output of the reference inter- ferometer is measured with a pig-tail photodiode and is then given by [3]where zz,,r is the effective refractive index of the fiber, zzg the group refractive index (about 1% higher than nefr in silica), A, the central vacuum wavelength of the light, zi,, the autocorrelation function taking the spectral characteristics of the emission into account and AL the physical path difference between the two interfering paths. Further similar interference terms appear in Eq.(1) in the special cases when AL, <L, or AL, < L,. When the optical path difference between the arms in the reference interferometer corresponds to the one induced by the two fibers installed in the structure (within the coherence length of the source), interference fringes appear. Scanning AL, with the mirror of the reference interferometer it is possible to obtain AL = 0either with AL, = AL, or with AL, = -AL,, and thus two interference fringe packets as described by Eq. (1). The mirror position corresponding to AL, = 0 also produces an interference and is used as a reference. These three fringe packets arc detected by means of a lock-in amplifier synchronized with the mirror displacements. The mirror displacements and the digitalization of the lock-in output are carried out by means of a portable personal computer. Since the reference signal is gcnerated separately and does not have a constant phase relation to the interference signal, only the envelope of the demodulated signal has a physical meaning and corresponds to the envelope of the fringe pattern. A lock-in plot showing the three typical peaks is shown in Fig. 2. Each peak has a width of about 30 pm. The calculation of its center of gravity determines its position with a precision better than 10 pm. This precision is the limiting factor of the whole measurement technique. Since AL, is known with micrometer precision, it is possible to follow AL, with the same precision.Fig. 1. Experimental setup of the low-coherence double Michelson interferomctcr. D. Innudi et al. 1 Semors andFig. 2. Typical fringe cnvclope as a function of the mirror position. The distance between the central and the lateral peaks corresponds to the length difference between the measurement and the reference fibers mounted in the table. Any change in the length of the structure results in a change in the position of these peaks. Any change in the losses of the fibers will result in a change of the height of the peaks. The central peak is fixed and used as a reference.The path difference AL, is proportional to the de-formation of the structure AL, with the relation between the two given by [4]where p is Poisson’s ratio and pij is the strain optic tensor (Pockcl’s coefhcients). The coefficient 5 takes into account the variation of the effective index neff in a fiber under strain.A degradation of one or both fibers (due to aging, for example) will result in a lower visibilityof the fringes but will not affect its position. The information about the deformation of the structure is encoded in the coherence properties of light and not in its intensity as in the majority of the sensors applied to date in civil-engineering structures, mostly based on microbend losses and/or optical time-domain reflectometry (OTDR) techniques. Interference peaks resulting from reflections as low as -30 dB of the source power can be detected by our system without phase modulators. By modulating the phase in one of the four arms of the two interferometers, one can increase the dynamic range of the device to more than 100 dB [5].Even if the polarization dispersion and bend-induced birefringence in the sensing fibers could reduce the visibility of the interference fringes or even split the fringe packets, none of those effects was observed in our experiment. No adjustment of polarization between the reference and the sensing arm was then necessary. A good mechanical contact between the measurement fiber and the structure under test is fundamental. In this study a number of installation procedures have been tested and optimized for the different measurements (shrinkage, elasticity modulus, etc.). The mounting techniques can be divided into two main categories: full-length coupling and local coupling.During our tests five out of six optical fiber pairs with a 0.9 mm nylon coating, being mounted on the external face of a 20 m long plastic pipe and protected only with thin rubber bands (see Fig. 3(a)), survived the concreting process. During the setting process the concrete envelops the fiber and realizes the desired mechanical contact. Those fibers showed a minor increase in the scattering losses and the appearance of small parasite peaks. The measurements on those fibers were consistent with the results obtained with other installation techniques (see below). It seems that for full-length coupling the nylon coating transmits the structure deformations (extension and shortening) entirely to the fiber core. This installation technique is very promising when compared to the usual procedure, consisting of a pipe protecting the fibers during the pouring of concrete and being removed before the setting process begins. This second method seemsmore adapted to small samples than to full-scale structures. Eleven otherfiber pairs were glued at the two ends of the table after removing locally the protective coating layers of the fibers (see Fig. 3(b)). The silica fiber was ftxed with epoxy glue to a metallic plate mounted on the end facesof the concrete structure. The gluing length was about 20 mm. Apre-strain (between 0.1 and 0.4%) has been given to those fibers during the gluing process to keep them under tension and allow the measurement of both expansion and shrinkage of the structure. This type of local coupling proved to be the most reliable, but was not adapted to following thedeformation during the pre-stressing of the table because of the important surface deformations occurring during this operation. The problem has been overcome by gluing other fibers inside the pipes at about two meters from the surfaces, i.e., far from the force insertion region (see Fig. 3(c)).Fig. 3. Schematic representation of three of the installation techniques used:(a) direct concreting of the measurement fiber mounted on a plastic pipe; (b) fiber glued at the table surface; (c) fiber glued inside the pipe at 2m from the pipe ends.Fig. 4. Top and side views of the concrete table measured in the experiment and position of the sensing-fiber pairs A, B, C and D. Fibers A, B and C arc glued at the surface of the structure, while fiber D is glued inside a pipe, 2 m away from the surface of the slab. Twelve more fihcr pairs were installed, but are not shown for simplicity.To study the possible effect of creep in strained fibers [6], one fiber has been mounted on a mechanical support that allows the fiber to be tightened only at the time of the measurement. No difference between this fiberand those permanently strained has been observed over a period of six months, confirming the assumption that no creep occurs for fiber strains below 1%. Since the scanning range of the mirror is 5 mm, it was easy to cleave the 20 m long fibers within this margin. The Fresnel reflection of the cleaved fibers combined with the high dynamic of the system allow a measurement of AL,,. This value of AL, can than be used to correct the cutting and obtain pairs with length differences below 1 mm. Two ferrules were then installed on the fiber ends and mounted in front of a polished inox surface. Chemical silver deposition was also used to produce mirrors on the cleaved fiber ends.Fig. 6. Comparison between the measurements performed on the structure by optical fibers and the ones performed on 360 mm and 500 mm samples in a mechanical micrometer comparator. The measurement on the samples was possible only during the first two months.3. ResultsSeveral long- and short-term measurements have been carried on a 20 m x 5 m x 0.5 m, 120 ton concrete slab intended to be used as a vibration-isolated base for optical analysis (in particular by holographic and speckle interferometry) of large structures [7].This structure has been concreted indoors, allowing controlled environmcntal conditions and known concrete composition to be achieved. Samples have been prepared with the same material composition and are under permanent test for their mechanical properties (resistance, shrinkage and elastic coefficient). This allows a direct comparison between the results on the full-scale structure and the samples. The table has been pre-strained 23 days after concreting in both length and width. It was possible at this time to measure the elastic coefficient of the material in full scale. Fig. 4 shows a schematic representation of the table and the position of the fibers referred to in the experimental results. At the time of writing, the table has been under test for six months. Over this period the shrinkage in the longitudinal direction (i.e., over 20 m) has been about 6 mm. We show in Fig. 5 the results of the measurements for three (glued) fibers over 175 days. The table has a T profile (Fig. 4). It is evident from Fig. 5 that thefibers mounted near the borders of the table, i.e., were the thickness is smaller, registered a larger shrinkage, as expected according to the concrete theory. Adjacentfibers give consistent results independently of the installation technique. No difference has been noticed between the fibers under permanent tension and those loosened between the measurements, suggesting that no creep of glass fibers occurred. The shrinkage measured with the fiber system has been compared during the first two months with the results obtained with a mechanical comparator mounted on two samples of 360 mm and 500 mm, respectively.The observed deformations have been scaled to 20m and are compared in Fig.6 to the results obtained with fibers B and C. Very good agreement is found between the two measurements. A theoretical comparison between the experimentalresults and the Swiss civil engineering standards has also been carried out. The experimental data and the standards are in agreement within f 10%. A more accurate simulation including the physico-chemical properties of the concrete used is under development. The table was pre-stressed 23 days after concreting. The five steel cables running over the length of the table and the forty cables running over its width were stretched with a force of 185 kN (18.5 Tons) each. The fibers glued to the surface and those in direct contact with concrete over the whole length measured an expansion of the table instead of the expected shrinkage. This is due to the important surface deformations occurring near the force-insertion points, i.e., near the pre-stress heads that were placed near the fiber ends. Fiber D glued inside the plastic pipe at 2m from each endwas not subject to these local effects and measured a shortening of 0.23 mm. The theoretical calculation based on an elastic coefficient of 30 kN/mm2gives a shortening of 0.28mm at the borders and 0.19 mm at the center of the table. Since fiber D was placed in an intermediate position, the experimental value can be considered to be in good agreement with the theory.4. ConclusionsA new deformation sensor adapted to the monitoring of civil-engineering structures has been proposed. it is based on low-coherence interferometry in standard lowcost telecommunication fibers. The resolution of the measurements is 10 pm, the operational range is 60mm and the stability has been tested over six months without noticeable drift. The reading unit is compact and portable, needing no optical alignment before the measurements. It is controlled by a portable personal computer, which is also responsible for the data trcatment. The same reading unit can be used to monitor multiple fiber lines by simple manual unplugging. This technique is furthermore practically insensitive to increased losses due to degradation of the fibers. A test study has been carried out on a 20m ~5m X 0.5m concrete slab, giving consistent results when compared to other measurement techniques based on samples or to concrete theories. It was possible to follow concrete shrinkage over six months (the cxper- iment will continue for about five years) and to measure the elastic coefficient on the full-scale structure. Different fiber-installation techniques adapted to the measurement of various parameters have been tested in building-site conditions. This technique appears very promising for the mon-itoring of civil-engineering structures such as bridges, dams and tunnels, allowing internal, automatic and permanent monitoring with high precision and stability over long periods.AcknowledgmentsThe authors are indebted to R. Passy and R. Delez for their assistance, encouragement and helpful dis-cussion. We acknowledge the IMM Institute in Lugano (Switzerland) for placing the table at our disposal and for the measurements carried out on concrete samples. We are grateful to Dr M. Pedretti and Ing R. Passera for their personal engagement in the project. We also thank Cabloptic in Cortaillod (Switzerland) for sup-plying all the optical fibers used in the experiment. This research has been performed with the financial support of CERS (Commission pour 1’Encouragement de la Recherche Scientifique).References[1] A.Koch and R.Ulrich,Fiber optic displacement sensor with 0.02mm resolutionbuy white-light interferometry,sensors and actuators A,25-27(1991)201-207[2]N.Gisin,J.-P.Von der weid and J.-P.Pellaux,Polarization mode dispersion ofshort and long single-mode fibers,J.Lightwave technol,9(1991)821-827.[3] A.S.Gergcs,F.Farahi,T.P.Newson,J.D.C.Jones and D.A.Jackson, Fiber-opticinterferometric sensors using low coherence source:dynamic range enhancement,Int. J.Op-toelectron,3(1988)311-322.[4] C.D.Butter and G.B.Hacker, Fiber optics strain gauge,Appl.Opt,17(1978)2867-2869.[5]H.H.Gilger,G.Bodmer and Ch.Zimmer, Optical coherance domain retlectometry asa test method of integrated optics devices,Proc.2nd Opt. Fibre Meas. Conf:OFMC 93, Turin, Ztuly, Z993, pp.143-146.[6]J.-P.Jaguin and A.Zaganiaris,La mecanique de rupture appliquee aux fibresoptiques, Verres Refract, 34 (Jul-Aout)(1980).[7]L.Pflug and M.Pedretti, Construction of a loo-tonnes holographictable,ZS&TISPIE Znt.Symp. Electronic Imaging, SanJose,CA,USA,1993,pp.50-54.传感器和执行器 A 44（1994）12.5-130用低变形传感器监测民用工程结构变形的一致性D.Inaudi a, A.Elamari b, L.Pflug b, N.Gisin b, J.Breguet b, S.Vurpillot aa IMAC、实验室的应力分析,瑞士联邦理工学院,CH-1015瑞士洛桑b GAP,群应用物理-光学部分,日内瓦大学，CH-1205瑞士日内瓦举行1993年1月25日实验;1994年3月8日修订,1994年3月25日发表文摘一个光纤变形的分辨率的传感器,10µm和运行范围的60毫米已经实现了。
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本科生毕业设计（论文）外文科技文献译文译文题目混凝土中后置式机械锚栓测试准则的注释(外文题目) Commentary on Qualification of Post-installed Mechanical Anchors in Concrete学院(系) 土木工程学院（建筑工程系）专业土木工程学号091036学生姓名陈恩慈日期2013年6月14日指导教师签名日期┊┊┊┊┊┊┊┊┊┊┊┊┊装┊┊┊┊┊订┊┊┊┊┊线┊┊┊┊┊┊┊┊┊┊┊┊┊目录R1R1.1 (1)R1.4 (1)R2R2.1R2.1.4 (1)R2.1.5 (1)R2.1.8 (1)R2.1.12 (1)R2.1.16 (1)R2.2 (2)R3R3.1 (2)R4R4.1 (3)R4.2 (7)R4.2.2 (7)R5R5.1 (7)R5.1.1 (7)R5.1.2 (7)R5.1.3 (7)R5.2R5.2.2 (9)R5.2.3 (9)R5.2.3.1 (10)R5.2.3.4 (10)R5.4 (10)R5.5R5.5.1 (10)R5.5.3 (10)R5.5.3.2 (12)R6R6.3R6.3.1 (12)┊┊┊┊┊┊┊┊┊┊┊┊┊装┊┊┊┊┊订┊┊┊┊┊线┊┊┊┊┊┊┊┊┊┊┊┊┊R7R7.2 (12)R7.2.1 (12)R7.3R7.3.1 (12)R7.3.2 (12)R8R8.2 (12)R8.3 (13)R8.4 (13)R8.5 (13)R8.5.3 (13)R8.6 (13)R9R9.2 (14)R9.2.2 (14)R9.3 (14)R9.4 (14)R9.5 (15)R9.6 (15)R11R11.0 (15)RA1.2 (15)RA1.3 (15)RA3.2 (15)注释参考文献 (17)┊┊┊┊┊┊┊┊┊┊┊┊┊装┊┊┊┊┊订┊┊┊┊┊线┊┊┊┊┊┊┊┊┊┊┊┊┊混凝土中后置式机械锚栓测试准则的注释R1.1ACI355.2阐述了运用ACI 318附录D中的设计方法来测试后置式机械锚栓所需的试验流程。
在ACI 318附录D中，假定锚栓在开裂的或者不开裂的混凝土中均已进行试验。
这些试验在混凝土试样中进行，这些仿真试样由实验室控制以模拟实际混凝土结构中可能发生的开裂或者不开裂的情况。
后置式机械锚栓展现了一系列的工作原理，特有设计以及性能特征。
针对于此，在ACI 318 附录D中以锚栓性能分类为基础，定义了锚栓承载力折减系数。
ACI 355.2意在完善ACI 318 附录D中确定某一锚栓的可靠性所需的资料，并且将该锚栓进行合适的归类。
虽然这一试验流程包含了在开裂混凝土中进行的试验，但是产生和控制裂纹的详细过程及指引并未发布。
这一内容预计将由ACI 355委员会作为新项目来发表或在ASTM 委员会E06.13中发表并包含在ASTM E 488中。
R1.4该设计方法被视为符合ACI 318附录D的锚栓设计要求，并且该方法是根据对最大直径为2 in. (50mm) 埋置深度不超过25 in. (635mm) 的锚栓数据库的分析得出的。
ACI 355.2可用于上述最大尺寸限制的锚栓。
ACI 355.2并没有给出最大锚栓直径和埋置深度的限制，对于尺寸超出上述限制的锚栓，应由试验中心来决定该试验是否仍然适用以及是否有可替代的更适合的分析和试验。
最小的锚栓直径1/4 in. (6mm)是出于实用性考虑，与结构上锚栓使用的限制有关。
R2.1.4 特征值被用于ACI 318附录D的设计方法。
特征值比平均值小1%并且基于试验进行的次数、准则制定者选用的置信水平以及可接受的失败率。
这里选定特征值或者5% 分位点（有95%的可能性大于该值，置信水平为90%)来进行锚栓的设计。
R2.1.5 混凝土破坏包括在拉力作用下的混凝土锥体破裂、由拉力或者剪力引起的边缘破裂，或者这些破坏的综合，如图5.3和5.4所示。
R2.1.8 当锚栓不能与混凝土牢固咬合直至产生钢材破坏或混凝土的锥体破坏，那么就会发生拔出式破坏。
在低于使混凝土发生锥体破坏的荷载下，整个锚栓从钻孔中滑出。
当发生混凝土锥体破坏时可能伴随部分拔出式破坏，则此时它的埋置深度小于发生完全混凝土锥体破坏时的埋置深度。
R2.1.12统计等效的决定因素是基于使用标准的统计程序和等式进行z或者t统计。
然后将计算所得t统计的值与在给定置信水平和相同样本容量下的列表值进行比较。
这个过程是为了提出一个假设并检验这个假设是否正确。
该假设认为对照试验的平均值大于（或小于）第二系列的锚栓检验的平均值。
t检验是统计检验，用来检测两个样本是否来自相同的总体。
R2.1.16 根据ACI 355.2，在不开裂的混凝土中使用的锚栓是在不开裂的混凝中进行试验，试验所用的混凝土始终保持不开裂的状态，除非由锚栓的破坏模式导致混凝土开裂。
┊┊┊┊┊┊┊┊┊┊┊┊┊装┊┊┊┊┊订┊┊┊┊┊线┊┊┊┊┊┊┊┊┊┊┊┊┊R 2.2——符号A se=对于因膨胀机制有横截面减小的膨胀型锚栓，制造商应提供有效的横截面面积。
对于螺栓，ANSI/ASME B1.1把A se定义为：20.97434setA dnπ⎛⎫=-⎪⎝⎭这里，n t是每英寸的螺栓数。
R3.1 ACI 318 附录D要求用于地震作用下的锚栓，能抵抗模拟的循环地震作用。
经验表明受到典型地震作用的钢筋混凝土结构，其塑性铰区的裂缝宽度发展大大超出了ACI 355.2中的预期。
图R1—总体试验项目流程图┊┊┊┊┊┊┊┊┊┊┊┊┊装┊┊┊┊┊订┊┊┊┊┊线┊┊┊┊┊┊┊┊┊┊┊┊┊R4.1 ACI 355.2 根据一个四步骤的程序（包括四种试验）来检测机械锚栓结构的适用性（在ACI 318 设立的使用限制内）并且建立可用于ACI 318中所述设计方法的锚栓性能分类。
四种试验分别是：鉴定试验，对照试验，可靠性试验和使用状态试验。
图R1至R6表示了试验顺序的流程图。
图R2—对照试验流程图┊┊┊┊┊┊┊┊┊┊┊┊┊装┊┊┊┊┊订┊┊┊┊┊线┊┊┊┊┊┊┊┊┊┊┊┊┊鉴定试验需要测定锚栓是否符合制造要求并且要求设立质量保证的基准。
对照试验有两个作用。
一是确定用于大边距和大间隔的单锚栓设计中的特征抗力。
二是用于与可靠性试验的结果进行比较。
对于对照试验，锚栓应该根据制造商的说明来进行安装。
可靠性试验有两个作用。
一是建立ACI 318中使用的锚栓分类，二是用来测定锚栓在持续荷载和可变荷载作用下的可靠性。
在安装或者使用期间，无论是在正常还是不利的情况下，锚栓都应该具备安全和有效的性能。
相关因素受以下变量影响：•在混凝土中的安装条件•钻孔的直径•锚栓所受的持续荷载和可变荷载•裂缝的宽度（仅对于在开裂或不开裂的混凝土中使用的锚栓的试验）；•与结构长期荷载及可变荷载相关的裂缝宽度（对于在开裂或不开裂的混凝土中使用的锚栓的试验）。
图R3—安装施力减小下可靠性试验流程图┊┊┊┊┊┊┊┊┊┊┊┊┊装┊┊┊┊┊订┊┊┊┊┊线┊┊┊┊┊┊┊┊┊┊┊┊┊为了减少试验项目的范围，我们将锚栓性能的影响因素与这些试验用最严格的组合条件进行组合。
检测锚栓可靠性以及为其分类的过程考虑了不同制造商不同安装过程的现场偏差。
然而，ACI 355.2并没有涵盖安装粗差，这些误差能够由适当的训练以及现场检查避免。
这样的粗差包括但不限于：钻孔的直径错误；不恰当的钻孔方法；不适用的支承工具；不适宜的支承方式；以及没有做到制造商要求的清洁、干燥条件或其他的钻孔准备工作。
图R4—对孔洞大小敏感度的可靠性试验流程图┊┊┊┊┊┊┊┊┊┊┊┊┊装┊┊┊┊┊订┊┊┊┊┊线┊┊┊┊┊┊┊┊┊┊┊┊┊为了展示正常试验状况，我们进行了重复荷载试验（表4.1，试验6），该试验下测得的裂缝宽度呈一个循环，试验的钻孔直径为d m。
表4.1的试验6规定了我们只测试最小的，中等大小的以及最大直径的锚栓。
对于给定的锚栓系统，制造商通常提供一系列直径，例如，1/4, 3/8, 1/2, 5/8, 3/4 , 1-1/4 in. 在这个例子中，我们将测试最小的（1/4 in.），中等大小的（5/8 in.）和最大的（1-1/4 in.）锚栓。
图R5—重复荷载下可靠性试验流程图┊┊┊┊┊┊┊┊┊┊┊┊┊装┊┊┊┊┊订┊┊┊┊┊线┊┊┊┊┊┊┊┊┊┊┊┊┊选定的条件组合意在模拟试验项目的同时保持整个连接可接受的安全水平。
假设承载力折减是有限的并且定义合理，那么在可靠性试验中观察到的锚栓承载力可能比对照试验中的低。
我们假设观察到的与对照试验测试条件相关的锚栓承载力发生的低概率是用来补偿折减的承载力, 实际上，这样能保持一个相对稳定的破坏率。
基于折减的程度，我们可以建立锚栓的分类。
当试验机构和制造商同时进行了使用状况试验时，他们中之一需要进行所需的最小试验数量的完整系列试验，而不是将这个完整系列试验拆开由他们分别执行。
本文中要求的基于试验数据误差系数的最小样本容量与ASTM E 488 的规定有所不同。
本文所要求的最小试验次数在表4.1中给出，表4.2所列则是得到充分结果所需的试验次数。
表4.1中试验7和表4.2中试验9（角试验）的样本容量为4，这是因为典型的试验样本试块有四个角。
混凝土试验试块的厚度是使锚栓符合标准的最小厚度，因此这些试验试块是专门灌注的。
因此，试验机构做这些试验只需要一块混凝土板。
R4.2如果锚栓样本是根据生产产品的相同方法准备的，那么这些原型就可用于试验。
鉴定和对照试验是在产品样品中进行，并且需要将这些样品的性能与试验原型的结果进行统计比较来判定是否需要另外的试验。
R4.2.2如果给定一个锚栓直径，而试验材料不同（如用碳素钢代替不锈钢）或者生产方法不同（如用冷成形代替机械加工），那么我们需要对每一种材料及制造方法分别进行对照试验和可靠性试验并统计结果进行比较。
如果结果在统计上没有差异，那么我们只需要对一组锚栓进行使用状态试验。
R5.1试验样本中对所用混凝土的控制是为了减少影响锚栓性能的变量，从而使实验结果易于重新检验。
不同的粘结材料和不同的混凝土掺合料都会影响锚栓的性能，从而增加测试数据的离散程度。
ACI 318的设计方法中关于承载力折减系数的建立就考虑了不同的混凝土混合物对锚栓性能的影响。
为了验证某一强度高于或低于ACI 355.2 中所给值的混凝土中的锚栓性能，以及在轻质混凝土中的锚栓性能，我们可以在特定的混凝土中进行ACI 355.2所述的试验。
更多的信息请参见Fuchs,Eligenhausen.和Breen的论文(1995) 。
R5.1.1所有的测试都在常规重量的混凝土中进行。
ACI 318附录D使用了一个广为接受的放大系数来确定轻质混凝土结构的承载力。
R5.1.2试验是在没有水泥替代物和混凝土掺合料的素混凝土中进行，锚栓可以在包含这些材料的混凝土中使用。