碳纤维布加固钢结构的黏结性能研究

杨勇新　 岳清瑞　 彭福明
（中冶集团建筑研究总院，北京100088）

摘要：与传统的钢结构加固方法相比，粘贴碳纤维布加固钢结构具有很大的优势和应用前景，如不会导致严重的应力集中、不会产生残余应力、施工方便、维护费用低等。碳纤维布与钢结构之间的黏结性能直接影响加固效果，但是目前国内对这方面的研究还未涉足。本文对粘贴碳纤维布加固钢板进行了静力拉伸试验，采用高强型和高模型碳纤维布及不同的端部锚固措施，考察了未损伤钢板和损伤钢板加固后的效果。得到了加固试件的屈服荷载和极限荷载，并对不同的破坏形式进行了分析。试验结果表明，粘贴碳纤维布加固能明显提高钢构件的屈服荷载。测量了碳纤维布的应变分布，得到了碳纤维布与钢板之间的黏结应力分布和碳纤维布的有效黏结长度，并与理论公式的计算结果进行了对比，二者吻合较好。
关键词：碳纤维布；拉伸应变；黏结应力；有效黏结长度

Study on the bond behavior of CFRP sheets to steel

Yang Yongxin　 Yue Qingrui　 Peng Fuming
(Central Research Institute of Building and Construction, MCC Group, Beijing 100088, China)

Abstract: There are several advantages in bonding carbon fiber sheets adhesively on　 deteriorated steel members than the traditional repair methods, such as, no stress concentrations, no residual stress, easy to construct and low maintenance cost. The bond behavior between carbon fiber sheets and steel affects the effectiveness of strengthening, but research on this subject is still lacking in China. Tensile tests of steel plates repaired with carbon fiber sheets were conducted. Different carbon fiber sheets and anchorage methods were adopted. The yielding loads and ultimate loads of the repaired specimens were measured. Failure modes of the specimens were analyzed. Tests results indicated that the yielding load of the repaired specimens increased obviously. The tensile strains of the carbon fiber sheets were measured. The bond stress distribution between the carbon fiber sheets and the steel plates and the effective bond length of the carbon fiber sheets were obtained. The calculation results were in good agreement with the experimental data.
Keywords: carbon fiber sheet; tensile strain; bond stress; effective bond length
E-mail: yangyongxin@tsinghua.org.cn

单层球面网壳的弹塑性稳定性

曹正罡　 范　 峰　 沈世钊
（哈尔滨工业大学，黑龙江哈尔滨150090）

摘要：为了解和掌握单层球面网壳在静力荷载作用下的弹塑性稳定性能，采用有限元软件ANSYS及自编的前后处理程序对典型单层球面网壳结构稳定性能进行对比分析，初步了解了球面网壳弹性与弹塑性稳定性能的主要差异。在此基础上进行了1000余例K8型单层球面网壳弹性、弹塑性全过程分析，同时考虑竖向均布荷载的不对称分布、初始几何缺陷等因素对球面网壳稳定性能的影响，掌握了以上因素变化对球面网壳弹塑性稳定性能的影响规律，并将其定量化。最后，通过对弹性、弹塑性稳定极限承载力的统计分析，提出适用于K8、K6型球面网壳的塑性折减系数，用以表示材料非线性对极限承载力的影响。这些成果的获得为进一步开展网壳结构的弹塑性稳定性能研究以及工程实践提供了理论依据和技术参考。
关键词：单层球面网壳；稳定；极限承载力；非线性；静力荷载；弹塑性

Elasto-plastic stability of single-layer reticulated domes

Cao Zhenggang　 Fan Feng　 Shen Shizhao
(Harbin Institute of Technology，Harbin 150090，China)

Abstract: In order to further understand the elastic and elasto-plastic stability behaviors of single-layer reticulated domes under static loads, typical cases of single-layer reticulated domes are analyzed and compared by using the finite element software, ANSYS.　 Based on the results, more than 1000 elastic and elasto-plastic complete-process analyses for the Kiewitt single-layer reticulated domes have been carried out to study the influence of various factors, such as initial geometry imperfection and unsymmetrical action of loads, and quantitative results were obtained. Through a statistical analysis of elastic and elasto-plastic stability critical loads, a plasticity reduction coefficient for the Kiewitt single-layer reticulated domes is proposed to reveal the influence of material nonlinearity on critical loads.
Keywords: single layer reticulated dome；stability；critical load；nonlinearity；static load；elasto-plastic
E-mail: caohit@hit.edu.cn

自密实混凝土梁长期变形性能研究

余志武　 刘小洁
（中南大学，湖南长沙410075）

摘要：对13根自密实混凝土梁在长期荷载作用下的变形性能进行了试验研究，探讨了早龄期加载时混凝土的固化程度、预加应力以及结构超静定次数对梁的长期变形性能的影响。试验研究和理论分析表明：（1）同组梁实测结果的离散性很小，自密实混凝土品质优良。（2）早龄期加载时混凝土的固化程度、预加应力以及结构超静定次数对梁的长期变形性能有较大的影响。（3）自密实混凝土梁的挠度徐变系数在1.0～1.8之间，在工程中采用自密实混凝土时一般不需要对自密实混凝土的徐变加以特殊考虑。（4）采用修正的MC90徐变和收缩模型及龄期调整有效模量法结合截面分析能较准确地计算自密实混凝土梁的徐变挠度。同时为自密实混凝土工程设计和结构分析提供可靠的试验依据。
关键词：自密实混凝土；梁；长期变形；试验

Experimental study on the long-term behavior of self-compacting concrete beams

Yu Zhiwu　 Liu Xiaojie
（Central South University, Changsha 410075, China）

Abstract: This paper reports the test results of 13 self-compacting concrete (SCC) beams. The effects of the degree of solidification of concrete at early stage of loading, the prestress force and the degree of indeterminacy on the long-term behavior of self-compacting concrete beams are investigated. Experimental study and theoretical analysis indicate that: (1) the variability of test results for the same group of SCC beams is very small, attributing to the good quality of SCC, (2) the degree of solidification of concrete at early age of loading, the prestress force and the degree of indeterminacy have great impacts on the long-term behavior of self-compacting concrete beams, (3) the deflection creep coefficient of SCC beams is between 1.0 and 1.8, thus extra preventions considering shrinkage and creep behavior are probably not needed, and (4) the test beams are modeled by section analysis using a modified MC 90 creep and shrinkage model and a age-adjusted effective modulus method. The calculated results agree well with the tests.
Keywords: self-compacting concrete；beam；long-term deformation；experiment
E-mail: zhwyu@mail.csu.edu.cn

混凝土结构裂缝扩展全过程的新GR阻力曲线断裂判据

徐世烺　 张秀芳
（大连理工大学海岸与近海工程国家重点实验室，辽宁大连116024）

摘要：混凝土结构的受力特性与裂缝的发展密切相关。在对国际断裂力学领域里所提出的三种裂缝扩展阻力曲线理论加以总结的基础上，以能量为表征，基于裂缝黏聚力提出了描述混凝土结构裂缝扩展全过程的新GR 阻力模型。在该模型中，裂缝扩展阻力分为三部分：一部分是基体水泥凝胶材料裂缝发展需克服的表面能，一部分是克服细骨料桥联作用的能量消耗，另一部分是粗骨料桥联闭合作用消耗的能量。文中对粗细骨料所消耗的能量进行了详细推导，得出了不同区段裂缝扩展阻力的解析计算公式。根据实测试验结果，得到了混凝土新GR 阻力曲线。结果表明GR 曲线是材料的基本参数，与试件尺寸无关，并建立了适用于混凝土结构裂缝扩展全过程的断裂判据。
关键词：裂缝黏聚力；新GR 阻力曲线；断裂判据；混凝土；裂缝扩展全过程

The new GR crack extension resistance as a fracture criterion for
complete crack propagation in concrete structures

Xu Shilang　 Zhang Xiufang
（Dalian University of Technology，Dalian 116024，China）

Abstract: It is well known that the mechanical performance of concrete structures is closely associated with the propagation of cracks. Three crack extension resistance theories for describing concrete fracture toughening phenomena are summarized, and based on the concept of crack cohesive force, a new analytical extension resistance model, named GR model, is proposed for investigating the resistance variation with crack propagation during fracturing in concrete. In this model, the energy approach is utilized and the crack extension resistance is decomposed into three parts: the surface energy needed to overcome in the extension of cracks in the hardened cement paste, the energy consumed to resist the cohesive traction of fine aggregate in fracture zone, and the energy dissipated to overcome the cohesive traction of coarse aggregate in fracture zone. The contribution provided by cohesive traction in the fracture zone induced by both fine aggregate and coarse aggregate to R resistance is derived in detail. An analytical formula for calculating the R resistance is developed for different ranges. From the experimental results, the typical GR curve is obtained. The result indicates that the proposed new GR extension resistance has no dependence on the size of the specimens tested, and thus is a fundamental mechanical parameter of the material. And a new fracture criterion applicable for the entire crack propagation process in concrete is constructed.
Keywords: crack cohesive force；new GR extension resistance；fracture criterion；concrete；crack propagation process
E-mail: slxu@dlut.edu.cn

无单元法在中厚板模态分析中的应用

孙建东¹　 张伟星²　 童乐为¹
(1. 同济大学，上海200092；2.青岛理工大学，山东青岛266033)

摘要：将无单元法成功地应用于中厚板的模态分析，推导了无单元法的插值函数，利用权函数构造出了高阶连续的近似场函数，并在权函数中借鉴了自适应影响半径的思想；利用 Mindlin-Reissner中厚板理论，从变分原理出发导出了中厚板模态分析的控制方程；同时利用罚函数法引入本质边界条件，给出了不同边界条件下的罚因子矩阵，推导出的系统刚度矩阵具有对称正定和带状分布的特点，可对不同边界条件下的中厚板振动问题进行求解，得到其自振频率及相应振型，并编制了相应的计算程序和后处理程序，可在MATLAB环境下绘制各阶振型图，便于直观、形象地对其振动特性进行定性研究。数值算例表明无单元法用于中厚板模态分析是合理可行的，能适用于较大范围内的剪切系数和长宽比，其结果具有相当高的精度。
关键词：无单元法；中厚板；模态分析；罚函数法

Modal analysis of moderately thick plates by element-free method

Sun Jiandong¹　 Zhang Weixing²　 Tong Lewei¹
(1. Tongji University, Shanghai 200092, China;　 2. Qingdao Technological University, Qingdao 266033, China)

Abstract: The element-free Galerkin method (EFGM) is successfully applied to the modal analysis of moderately thick plates. The shape function of high-order continuity is formulated by means of the weight function. A method to incorporate the adaptive influential radius in the weight function is proposed. Based on the variation principle, the governing equation for modal analysis of plates is derived from the Mindlin-Reissner plate theory. Using the penalty function method, the stiffness matrix, a real symmetric positive definite matrix, is derived. This method may solve the vibration problem of moderately thick plates with different boundary conditions and may obtain its free frequencies and the corresponding vibration mode curves. A computer code of EFGM with post-processing is developed, by means of which, one may obtain the vibration mode curves under the MATLAB software to study the vibration characteristic of the plate. Numerical examples show that the EFGM is feasible and accurate.
Keywords: element-free Galerkin method; moderately thick plate; modal analysis; penalty function
E-mail: sunjd2001@163.com

修正Clough滞回模型下的地震力调整系数

赵永峰　 童根树
（浙江大学，浙江杭州310027）

摘要：采用反向加载时刚度退化的修正克拉夫（Modified-Clough，MC）滞回模型，计算了单自由度体系（SDOF）在四类场地下各74～106条地震波输入后的弹塑性动力时程响应，得到了不同自振周期、延性、阻尼比和后期刚度系数等参数组合下的地震力调整系数R。结果表明，影响R的决定性因素是结构的延性，延性越大R越大；阻尼比、后期刚度对R的影响是第二位的，而且只在短周期范围内比较明显。对R谱的横轴做标准化处理后，较好地保留了R谱在特征周期处的峰值特征，并提出了R的计算公式。为了分析耗能能力、刚度退化的影响，将延性和耗能能力作为两个独立变化的因素，分析了理想弹塑性（EPP）、剪切滑移（SSP）和无任何耗能能力的双线性弹性（BIL）模型下的R谱，与MC滞回模型下的R谱一起相互之间进行了对比。结果表明，在延性保持相同的情况下耗能能力在中长周期结构中对地震力调整系数几乎没有影响，这一结论对美日等国近几年引入一些注重延性而不单纯看重耗能能力的细部构造提供了理论解释。在中等周期范围内，刚度退化的MC结构比EPP结构的强度需求反而要小。
关键词：抗震设计；地震力调整系数；修正Clough滞回模型；延性

Seismic force modification factors for structures with modified-Clough hysteretic model

Zhao Yongfeng　 Tong Genshu
(Zhejiang University，Hangzhou 310027, China)

Abstract: Based on an elasto-plastic time-history earthquake analysis of a single degree of freedom system (SDOF), the seismic force modification factor R of the modified-Clough (MC) model, which can be employed to represent structures that exhibit stiffness degradation when subjected to cyclic loading, is investigated. A total of 370 earthquake records from 4 sites are employed to calculate the structure response and the factor R for different structure periods, ductility, damping ratios and the post-yield stiffness ratios. It is found that the most important factor in determining R is the ductility, while both damping and the post yield stiffness have a minor effect in the short period range. The R spectra are normalized by using the characteristic period Tg of the ground motion to maintain the peak behavior near Tg. Simplified formulae are proposed for the R spectra. Three other hysteretic models, including elastic perfectly-plastic(EPP), shear-slipped(SSP) and bilinear elastic(BIL), are analyzed to examine the effect of energy-dissipating capacity and stiffness degradation on the R spectra, and the results, together with the R spectra for MC model, are compared. It is found that the energy dissipating capacity has nearly no effect on the R spectra in the middle-to-long period range. This provides an explanation on the recent American practice that emphasizes more on the ductility than on the energy dissipating capacity. Comparison between EPP and MC models indicates a smaller strength requirement for the latter model within medium periods.
Keywords: seismic design; seismic force modification factor; the modified-Clough model; ductility
E-mail: tonggs@zju.edu.cn

结构形态创构方法
——改进进化论方法及其工程应用

崔昌禹¹　 严　慧²
（1. 日本佐佐木睦朗结构设计研究所，日本名古屋4680021；2. 浙江大学，浙江杭州310027）

摘要：在建筑方案设计中，采用结构计算的方法来帮助建筑师确定建筑的形态具有工程意义。模仿自然界的进化现象，本文提出了一种结构形态的创构方法。该方法利用有限元法，计算结构相关力学特性（如von Mises应力分布），通过进行等值线（面）分析来评价结构承受荷载的效率，利用对曲线（面）进行“保留、淘汰、补充”的操作使结构体逐步进化并演变成合理结构。文中对该方法在两个实际工程设计中的应用进行了详细分析，并从提高进化效率的角度讨论了初始形状的合理选择。该方法可以对不同设计变量（比如约束条件，空间条件）进行设定从而得出不同建筑形态，给设计人员提供多种可参考的合理方案。利用此方法所得到的结构形态通常可以抑制弯矩产生，保证应力分布均匀且以轴力效应为主。最后讨论了该方法的有效性和实用性。
关键词：形态优化；结构优化；非线性方法

An advanced structural morphosis technique
——Extended evolutionary structural optimization method and its engineering applications

Cui Changyu¹　 Yan Hui²
(1. Sasaki Structural Consultants, Nagoya4680021, Japan；2. Zhejiang University, Hangzhou310027,China)

Abstract: The design of architectural forms by using structural computations is helpful for architects at the schematic design stage. Derived from the principle of “nature evolution”, a new structural morphosis method is put forward. The finite element approach is employed to analyze the relevant structural mechanical properties such as the von Mises stress distribution. Resistance efficiencies of local areas are further evaluated by analyzing the contour lines or surfaces. The original structural geometry is modified iteratively by“preserving, eliminating or increasing” those areas according to their contributions to the structural resistance, so that a rational architectural form can be obtained. Two practical engineering designs obtained from this method are analyzed in detail. The choice of original structural geometry is also discussed, aiming at improving the evolving efficiency. With this method, the change of different kinds of design parameters, such as constraint or space conditions, may create different architectural forms, which is beneficial for designers. Generally, an architectural form constructed by using this method can keep the structure in a mostly uniform axial-stress state and with the bending moment controlled. The validity and practicability of the method are discussed.
Keywords: shape optimization；structural optimization；nonlinear programming
E-mail:　 1.ccy@topaz.ocn.ne.jp ；2.yanhuihang@zju.edu.cn

火灾下预应力板混凝土爆裂规律试验研究

郑文忠　 许名鑫　 石东升　 胡琼
（哈尔滨工业大学，黑龙江哈尔滨150090）

摘要：在火灾下预应力板迎火面的混凝土若发生爆裂，受力钢筋将裸露于火中，板将因钢筋被烧断而很快丧失承载力。完成了14块无黏结预应力混凝土简支单向板、1块先张预应力混凝土简支板和9块两跨预应力混凝土连续单向板的抗火试验，描述了8块简支板及3块连续板混凝土爆裂、受拉钢筋被烧断及裂缝分布与开展情况。得到了迎火面压应力水平越高或拉应力水平越低、常温下混凝土强度等级及含水率越高，混凝土越容易发生爆裂或爆裂越严重的初步结论。基于试验结果，首先提出了以常温下混凝土标准立方体抗压强度平均值为横坐标，以火灾下预压区板边缘混凝土正应力水平为纵坐标的混凝土爆裂上包线表达式和以常温下混凝土含水率为横坐标，以火灾下预压区板边缘混凝土正应力水平为纵坐标的混凝土爆裂上包线表达式；为便于设计应用，随后还提出了以常温下混凝土标准立方体抗压强度平均值为横坐标，以常温下预压区板边缘混凝土正应力水平为纵坐标的混凝土爆裂上包线表达式和以常温下混凝土含水率为横坐标，以常温下预压区板边缘混凝土正应力水平为纵坐标的混凝土爆裂上包线表达式。为初步判断火灾下混凝土爆裂的可能性提供了参考依据。
关键词：火灾；预应力板；混凝土；含水率；爆裂

Experimental study on spalling of concrete of prestressed slabs in fire

Zheng Wenzhong　 Xu Mingxin　 Shi Dongsheng　 Hu Qiong
（Harbin Institute of Technology, Harbin 150090, China）

Abstract: If the concrete of a prestressed slab spalls in fire, the reinforcement will be exposed to flame, and the slab would soon lose its bearing capacity due to breaking of reinforcement caused by burning. Fire experiments are conducted on fourteen simply supported unbonded prestressed concrete slabs, one simply supported pretensioned prestressed concrete slab and nine two-span prestressed concrete continuous slabs. The spalling of concrete, breaking of tension　 reinforcements, distribution and development of cracks for 8 simple slabs and 3 continuous slabs are described. Preliminary conclusions are: concrete spalls more easily or more seriously when the compressive stress is higher or the tensile stress is lower in the surface exposed to fire, and when the strength of concrete and water content in concrete at normal temperature are higher. Based on the test results, two expressions of top envelope curve for concrete spalling are presented by taking the average standard concrete cubic strength at normal temperature as the x-axis and the normal stress level of concrete extreme fiber in pre-compression zone of slab in fire as the y-axis, and taking the water content in concrete at normal temperature as the x-axis and the normal stress level of concrete extreme fiber in pre-compression zone of slab in fire as the y-axis; to facilitate design and application, two expressions of top envelope curve of concrete spalling are presented by taking the average standard concrete cubic strength at normal temperature as the x-axis and normal stress level of concrete extreme fiber in pre-compression zone of slab at normal temperature as the y-axis, and taking the water content in concrete at normal temperature as the x-axis and normal stress level of concrete extreme fiber in pre-compression zone of slab at normal temperature as the y-axis.
Keywords: fire; prestressed slab; concrete; water percentage; spalling
E-mail: zhengwenzhong@hit.edu.cn

体育场主看台弧形挑篷气弹模型风洞试验和响应特性

顾 明 朱川海
（同济大学土木工程防灾国家重点实验室，上海200092）

摘要：体育场看台挑篷是典型的风敏感结构。气动弹性模型风洞试验是研究其风振响应的有效方法，但由于挑篷结构质量轻、刚度小，气弹模型设计和制作均很困难，所以目前在实际工程抗风研究中很少应用。本文以一实际体育场主看台挑篷为对象，研究了这类轻柔结构的气弹模型的设计和制作方法，并通过风洞试验进一步了解体育场主看台挑篷的风振响应特性，获得了这类结构的风致响应的基本特征。
关键词：体育场看台挑篷；气动弹性模型；风致响应；风洞试验

Wind tunnel test on an aeroelastic model of grandstand cantilevered
roof of large stadium and features of wind-induced response

Gu Ming　 Zhu Chuanhai
（State Key Laboratory for Disaster Reduction in Civil Engineering, Tongji University, Shanghai 200092, China）

Abstract: Grandstand cantilevered roofs of large stadiums have become a kind of typical wind-sensitive structures due to their flexible and light features. Also due to the features, the design and manufacture of the aeroelastic model are difficult although the kind of models are effective to investigate responses of the structures under strong wind actions, and thus has been seldom used in practical application. A real grandstand cantilevered roof of large stadium is taken as the prototype of the present study. The aeroelastic model of the roof structure is designed and manufactured, and the wind tunnel test is then carried out. The test results are further compared with the computed results which have also been made by the authors to verify the reliability of the model and the test results. Some important conclusions are finally summarized.
Keywords: grandstand cantilevered roof of stadium；aeroelastic model；wind-induced response；wind tunnel test
E-mail: minggu@mail.tongji.edu.cn

碳纤维布与钢板黏结剪切性能研究

卢亦焱 张号军 刘素丽
（武汉大学，湖北武汉430072）

摘要：碳纤维布与钢板复合加固混凝土结构是一种新的加固形式，在其运用到实际加固工程时，关键是要保证碳纤维布与钢板之间的有效黏结。通过11组碳纤维布与钢板黏结剪切试验，分析了碳纤维布与钢板发生黏结剪切破坏的过程、破坏机理，并对碳纤维布的黏结宽度、碳纤维布的层数和黏结长度等对黏结剪切性能的影响进行了研究。研究结果表明，碳纤维布与钢板的有效黏结长度随着碳纤维布层数增加而增大，而与碳纤维布的宽度及粘贴长度无关；碳纤维布与钢板的极限黏结力随碳纤维布宽度增加而线性增大，且当黏结长度超过有效黏结长度后，极限黏结力不再随黏结长度增大而增加，但黏结破坏的延性得到改善。在试验研究的基础上提出了极限黏结力和有效黏结长度的计算公式，其计算结果和试验结果吻合较好，可为复合加固在工程上的应用提供参考。
关键词：碳纤维布；钢板；复合加固；剪切性能

A study on the adhesive shear performance of steel plates bonded by carbon fiber reinforced polymer

Lu Yiyan　 Zhang Haojun　 Liu Suli
（Wuhan University, Wuhan 430072, China）

Abstract: Combination strengthening RC structures with carbon fiber reinforced polymer and steel plate is a new rehabilitation method, in which the effective bond between steel plate and CFRP is critical. An experimental study was conducted on the shear behaviors of 11 groups of specimens. The stress distribution characteristics, failure process and mechanism were investigated. The influence of width, thickness and adhesive length of CFRP on the adhesive shear properties was analyzed. The results indicate that the effective adhesive length increases with the number of CFRP layers. The width and the adhesive length have no effect on the effective adhesive length. The ultimate bond capacity increases linearly with the width of CFRP, until the adhesive length surpasses the effective adhesive length.　 Moreover, the ductility can be improved with increasing adhesive length. Based on the experimental study, calculation formulas for ultimate bond capacity and the effective adhesive length are established. The theoretical calculation results are consistent with the experimental ones.
Keywords: carbon fiber reinforced polymer(CFRP)；steel plate；combination strengthening；shear performance
E-mail: yylu901@163.com

斜拉桥锚拉板式索梁锚固结构传力机理及疲劳可靠性研究

任伟平　 强士中　 李小珍　 李俊
（西南交通大学，四川成都610031）

摘要：针对锚拉板式索梁锚固结构部分区域应力集中严重，疲劳性能不明确等问题，对湛江海湾大桥锚拉板式索梁锚固结构分别进行了足尺比例静载和疲劳模型试验，研究了其结构特点、制造工艺、应力集中程度、塑性区大小和分布、关键构造细节的疲劳性能等。通过有限元计算，对影响结构性能的一些重要参数进行了分析。研究结果表明，该结构部分区域存在一定程度的应力集中，在1.7倍设计荷载作用下个别区域出现了屈服，经循环加载疲劳试验结构关键部位未发现疲劳裂纹，结构的静承载力和疲劳性能均能满足设计要求，并具有一定的安全储备。研究结果为类似结构的设计提供了可靠的参考数据，并对结构参数优化、改善结构受力性能等具有一定的指导意义。
关键词：锚拉板；斜拉桥；索梁锚固结构；传力机理；疲劳性能；应力集中

Mechanical behavior and fatigue reliability of tensile anchor plate structure in the cable-beam anchorage zones of cable-stayed bridges

Ren Weiping　 Qiang Shizhong　 Li Xiaozhen　 Li Jun
（Southwest Jiaotong University, Chengdu 610031, China）

Abstract: Stress concentrations and uncertain fatigue performance are the primary problems for tensile anchor plates at cable-beam anchorage zones in cable-stayed bridges. In order to investigate the mechanical behavior and fatigue reliability of the structures, a full-scale static-load model test and a fatigue model test of the tensile anchor plate structure of the Zhanjiang Gulf bridge ( a cable-stayed bridge in Guangdong, China) were performed. Problems such as structural features, manufacture processes, stress concentrations, distributions of plastic zones and fatigue performance of some structural details, were studied. Based on 3-D FEA results, the important parameters influencing the structural performance were analyzed. The test results showed that the areas of stress concentrations were fairly localized, plastic yield occurred in few regions under 1.7 times the design load, and no fatigue cracks were found after cyclic loading. The structural performance satisfies the design requirement.
Keywords: tensile anchor plate; cable-stayed bridge; cable-beam anchorage zone; mechanical behavior; fatigue performance; stress concentration
E-mail: renwp888@163.com

桥面沥青铺装设计新方法

赵锋军^1,2　易伟建¹　李宇峙²
（1. 湖南大学，湖南长沙410082；2. 长沙理工大学，湖南长沙410076）

摘要：提出一种不同于传统经验设计法的桥面沥青铺装理论设计方法。利用有限元方法计算分析桥面沥青铺装受力特性，发现“肋间距”与桥面板厚度是影响沥青铺装受力的关键因素，基于此结论，新设计方法采用两跨连续叠层梁作为铺装受力计算的基本模型。基于桥面沥青铺装疲劳开裂以纵桥向裂缝为主的工程实际，以及桥面沥青铺装的有限元计算结果，确定铺装顶面最大横向弯拉应变为控制指标，分别以铺装表面弯拉应变相等以及铺装底面弯拉应变相等的条件，利用弹性层状体系计算程序“BISAR”，计算得到铺装结构的 “当量土基模量”，从而将桥面沥青铺装设计与一般沥青路面设计相联系，形成较为系统的桥面沥青铺装力学设计系统。采用桥面沥青铺装力学设计方法的算例表明，钢桥面的“当量土基模量”较大，计算精度较高，水泥混凝土桥面的“当量土基模量”非常小，对计算过程的数据精度有更高的要求。
关键词：桥面沥青铺装；叠层连续梁；弹性层状体系；设计指标；设计系统

A new method for bridge asphalt pavement design

Zhao Fengjun^1,2　Yi Weijian¹　Li Yuzhi²
(1.Hunan University, Changsha 410082, China;
2. ChangSha University of Science Technology, Changsha 410076, China)

Abstract：Different from the traditional experimental design method, a theoretical method for bridge asphalt pavement design is developed. Based on an analysis of the mechanical characteristics of bridge pavement by using the finite element method (FEM), it is found that the‘interval of ribs’and the thickness of deck are key factors to the stress in bridge pavement. Based on this conclusion, a continuous laminated beam has been employed as the basic model of bridge asphalt pavement. In practice, longitudinal cracking is the major fatigue effect on bridge pavement, and the result of FEM confirms that; the maximum transverse strain on the top of pavement is identified as the design index. The modulus of the corresponding base in an elastic multilayer system is calculated when the maximal transverse flexural-tensile strain on top or bottom of bridge pavement is equal to the flexural-tensile strain in normal asphalt pavement. The designs of bridge pavement and normal asphalt pavement are related to each other. The example indicates that the modulus of the corresponding base is larger when the new design method is employed for steel bridges than for concrete bridges, and higher accuracy is required in computations for the latter.
Keywords：bridge asphalt pavement；continuous laminated beam；elastic multilayer system；design index；design system
E-mail: zfj_007@tom.com

钢筋混凝土桥墩基于位移的抗震设计方法

王东升¹　李宏男²　赵颖华¹　王国新²
（1.大连海事大学，辽宁大连116026；2.大连理工大学，辽宁大连116024）

摘要：通过改进能力谱法，给出了一个可以实现“小震不坏、中震可修和大震不倒”多级性能目标的钢筋混凝土桥墩直接基于位移的抗震设计方法。首先以钢筋和混凝土的应变幅值建立了钢筋混凝土桥墩不同破损极限状态的量化准则，并基于曲率延性系数和位移延性系数关系转化为墩顶位移的表述形式。再以屈服位移和位移延性系数作为设计参考变量，采用屈服谱加速度和屈服位移（Ay－Dy ）格式的地震需求谱求解系统在不同风险水平地震作用下的反应。最后以能力设计原理保证桥墩截面的抗剪强度需求。通过一个具体设计算例说明了建议方法的可行性。
关键词：钢筋混凝土桥墩；基于位移抗震设计；多级性能目标；改进能力谱法； 屈服位移；破损极限状态

Displacement-based seismic design method of RC bridge piers

Wang Dongsheng¹　Li Hongnan²　Zhao Yinghua¹　Wang Guoxin²
(1. Dalian Maritime University, Dalian 116026,China; 2. Dalian University of Technology, Dalian 116024, China)

Abstract: A direct displacement-based seismic design procedure of RC bridge piers fulfilling multiple performance objectives, which usually require that the structure can sustain a minor earthquake without any damage, a moderate earthquake with repairable structural damage, and a strong earthquake without collapsing, is developed by means of the improved capacity spectrum method. The procedure uses the yield displacement and displacement ductility factor as the design parameters and uses the inelastic seismic demand spectrum with yield spectral accelerations and yield displacements format to calculate the seismic demands of the pier under different earthquake levels. Seismic capacities of the pier are determined by acceptable structural damages, which are estimated quantitatively by using both the strains of concrete and the longitudinal steels in plastic hinge zones, and expressed as displacements at top of the pier by transforming from the relationship between curvature ductility factor and displacement ductility factor. The shear strength of the pier is also checked using the concept of capacity design in order to avoid brittle shear failure. The feasibility of the proposed method is validated by using an example on the seismic design of a single bridge pier.
Keywords: reinforced concrete bridge pier; displacement based seismic design; multiple performance objectives; improved capacity spectrum method; yield displacement; damage limited state
E-mail: dswang@newmail.dlmu.edu.cn

软土加固过程中微结构变化的分形研究

薛　茹¹　胡瑞林²　毛灵涛³
（1. 郑州航空工业管理学院，河南郑州450015； 2. 中国科学院地质与地球物理研究所，北京100029；
3. 中国矿业大学，北京100083）

摘要：土体内部孔隙的特征及分布情况是土体微结构变化的内因，也是决定土体物理力学性质的主要因素。在软土性质发生改变时，孔隙的变化是最直接、最显著的。所以，对土体微观结构进行研究，应着重研究土中孔隙的变化。由于土中孔隙的复杂性及非确定性，很难用传统的几何方法对其研究和描述。为研究加固前后软黏土微结构的变化情况，在珠江三角洲某高速公路软土路基利用动力排水固结法加固的施工现场，取不同深度内加固前后土样进行压汞测试，用分形理论对压汞测试数据进行分析，探讨软土中孔隙的分布特征，在此基础上提出了土中孔径划分的方法，进而探讨动力排水固结法加固软土地基的微结构变化，建立了加固后土样的孔隙度分维数与土体固结度之间的关系，研究结果表明土中孔隙分布具有分形特征，用孔隙度分维数可以实现对地基加固程度的预测。
关键词：软土路基加固；孔隙度分维；压汞测试；固结度；动力排水固结法

Fractal study on the microstructure variation of soft soils in consolidation process

Xue Ru¹　Hu Ruilin²　Mao Lingtao³
(1. Zhengzhou Institute of Aeronautical Industry Management, Zhengzhou 450015, China;
2. Institute of Geology and Geophysics , CAS， Beijing 100029, China;
3. China University of Mining and Technology, Beijing 100083, China)

Abstract: The characteristics and distribution of pores in soil are the internal cause of microstructure variation, and thus they are also the key factors in the determination of the physical and mechanical characteristics of the soft soil. To describe the micro-structure of the soil, the pore variation should be emphatically studied. Because of the complexity and uncertainty of pore behavior, it is difficult to describe the pore behavior with the traditional geometric methods. Taking the subgrade soft soil from the Zhujiang River Delta treated with Dynamic Drainage Consolidation as examples, the microstructures of un-consolidated and consolidated soft soils are studied by means of the mercury intrusion method.　 The fractal characteristics of pore distribution are studied through the data analysis by means of the fractal theory.　 The method of pore classification is proposed, and the relationship between porosity fractal dimension and consolidation degree formulated. The results indicate that the fractal characteristics of pore distribution are significant, and porosity fractal dimension can be employed for predicting the degree of consolidation of the soft soil.
Keywords: soft roadbed reinforcement; porosity fractal dimension; mercury intrusion method; consolidation degree; dynamic drainage consolidation
E-mail: xr6239@163.com

超深基坑复合土钉支护结构原位试验研究

姚　刚¹　刘晓纲¹　韩　森²
（1. 重庆大学，重庆 400045；2. 吉林大学，吉林长春 130026）

摘要：通过对深圳假日广场超深基坑预应力锚索复合土钉支护结构进行全方位的原位测试试验，收集了关于土钉拉力、锚索应力、孔隙水压力、面层土压力的大量数据，旨在研究钉—锚—土三者的工作性状、相互作用机理，以及随基坑开挖、锚索张拉、降雨、卸载等外界环境变化对支护结构的响应规律。试验结果表明预应力锚索复合土钉支护结构具有开挖效应、时间效应、空间效应、降雨滞后效应；指出土钉拉力并非随基坑开挖深度递增，潜在滑移面并非通过基坑坡脚；揭示了预应力锚索的主要作用不在于分担或改善支护结构受力状态，而在于提高边坡抗滑移稳定性和减小边坡位移，并就设计和施工提出了一些合理建议和应注意的问题。
关键词：超深基坑；预应力锚索复合土钉支护；原位测试试验

In-situ test of composite soil nailing for a deep foundation pit

Yao Gang¹　Liu Xiaogang¹　Han Sen²
(1. Chongqing University, Chongqing 400045, China; 2. Jilin University, Changchun 130026, China)

Abstract: In-situ test was conducted for the prestressed anchor rope composite soil nailing of a deep foundation pit for the Shenzhen Holiday Plaza to study the characteristics, the mechanism of interaction between soil nailing, prestressed anchor rope and soil, and the response of retaining structure to changes in the external environment, such as foundation pit excavation, anchor rope tension and rainfall. Data were collected on tension of soil nailing, stress of anchor rope, pore water pressure and earth pressure. The test reveals the excavation effect, time effect, three-dimensional effect and rainfall lagging effect of the prestressed anchor rope composite soil nailing. The test also indicates that tension in soil nailing does not increase with the excavation depth, and the potential slip plane does not pass through the base of the slope. The major function of the prestressed anchor rope is not for resisting shear or reducing stress in the retaining structure, but rather for improving the stability of slope.
Keywords: ultra-deep foundation pit; prestressed anchor rope composite soil nailing; in-situ test
E-mail: yaocqu@vip.sina.com.cn

均匀柱荷载作用下梁板式筏形基础破坏性状的试验研究

王曙光
（中国建筑科学研究院地基基础研究所，北京100013）

摘要：梁板式筏形基础广泛应用于多层建筑和高层建筑的裙房部分的基础，其受力机理及破坏性状是急待解决的问题。通过室内模型试验，对天然地基上梁板式筏形基础与地基共同作用问题进行了研究。室内试验是在地基所试验室的实验坑内进行的，采用人工换填的均匀粉质黏土模拟天然地基，试验模型为单跨梁板式筏形基础，加载方式采用油压千斤顶在梁节点处同步加载以模拟均匀柱荷载，柱荷载均匀施加至试验模型发生结构破坏，测试内容为基底反力及沉降。通过试验及结果分析，发现了梁板式基础的荷载传递顺序及破坏性状，得出了梁板式筏基在大、小荷载作用下的不同变形特征和基底反力分布规律，并根据试验数据所反映出的变形规律，给出了大、小荷载作用下简化的基底反力分布模式。
关键词：梁板式筏基；共同作用；变形；接触反力

Experimental study on the failure behavior of waffle-slab raft foundations under uniform column loads

Wang Shuguang
(Institute of Foundation Engineering, China Academy of Building Research, Beijing 100013, China)

Abstract: Waffle-slab raft foundations are widely used in multi-story buildings and skirt buildings attached to high-rise buildings, and the load transition mechanism and failure behavior deserve serious studies. The interaction between foundation soil and waffle-slab raft is studied based on large-scale model tests. The model tests were performed in a foundation pit in the laboratory of the Foundation Engineering Institute, China Academy of Building Research, and silt-clay filled artificially was used to simulate the foundation soil. The model is a one-span waffle-slab subject to uniform column loads that make the model cracks, the contact pressure and displacement are measured. The failure behavior and the load transition mechanism are discussed. The different deformation and contact pressure characteristics of the waffle-slab raft under lower or higher loads have been identified, and a simplified contact pressure distribution is provided.
Keywords: waffle-slab raft；interaction；deformation；contact pressure
E-mail: wshgcabr@yahoo.com.cn

深厚软土超长预应力高强混凝土管桩轴向受力性状的试验研究

蔡　健¹　周万清¹　林奕禧²　黄良机²
（1．华南理工大学，广东广州 510640；2．珠海市建设工程质量监督检测站，广东珠海 519015）

摘要：通过在管桩的钢筋笼里面添加带应变计的附加钢筋，对珠海保税区深厚软土地基中超长预应力高强混凝土（PHC）管桩进行了轴向静载试验和桩身轴力的测试，探讨了深厚软土地基中超长PHC管桩的竖向承载特性和荷载传递机理。结果表明在深厚软土地基中，超长PHC管桩表现出端承摩擦桩的承载性状，因此应当选择压缩性较小的土层作为持力层；超长PHC管桩的桩端土刚度对桩侧摩阻力的发挥有极大的影响，提高桩端土刚度对桩侧摩阻力有明显的增强作用；适当地增加桩长可以提高桩基的极限承载力；在长细比较大的超长PHC管桩设计中，除了从极限承载力和桩顶沉降来考虑外，还应该注意桩身强度的影响；同时，在沉降计算中，要充分考虑桩身压缩引起的沉降。该试验方法和试验结果对今后PHC管桩的研究和设计应用具有重要的指导意义。
关键词：PHC管桩；超长桩；软土地基；试验研究；荷载传递

Experimental study on the axial compressive behavior of super-long PHC pipe piles in deep soft soils

Cai Jian¹　Zhou Wanqing¹　Lin Yixi²　Huang Liangji²
(1.South China Univ. of Tech. , Guangzhou 510640, China;
2.Zhuhai Municipal Construction Engineering Quality Supervision & Test Station, Zhuhai 519015, China)

Abstract: Based on the data analysis of loading tests on PHC(prestressed high strength concrete)pipe piles, conducted through adding two additional reinforcement steel bars with strain gauges in the reinforcement cage of the pile in the deep soft soil foundation of the Zhuhai free trade zone, the bearing capacity and load transferring mechanism of the piles are discussed. Results show that the super-long PHC pipe piles behave as end-bearing frictional piles, so the piles should be driven to a soil layer with little compressibility. The stiffness of the soil at the pile tip affects the skin friction, therefore, improving the stiffness of the soil at the pile tip may significantly improve skin friction. The bearing capacity of the super-long PHC pipe piles increases with increase of the length of the pile. It is important to consider the strength and the settlement of the pile in design, and the settlement owing to the compression of pile should be considered in the calculation of the settlement.
Keywords: PHC pipe pile；super-long pile；soft soil ground；test and research；load transfer
E-mail: cvjcai@scut.edu.cn

地铁开挖对上部桩基变形的影响研究

李　宁^1,2　王　柱¹　韩　煊^1,3　柳厚祥¹
（1. 西安理工大学，陕西西安710048；2. 中国科学院兰州寒区旱区环境与工程研究所，甘肃兰州730000；
3. 北京市勘察设计研究院，北京100038）

摘要：采用有限元数值模拟分析技术，研究因隧道开挖施工而引起周围土体及不同位置单桩的变形规律。在分析中考虑了不同位置单桩和桩—土相互作用的影响。系统数值试验研究成果显示：（1） 地铁开挖对上部桩土沉降影响明显，引起桩两侧的明显沉降变形差，使桩土可能产生负摩阻力或分离—临洞侧丧失摩阻力。（2）由于左侧桩的存在使隧道两侧土体的刚度明显不对称，故隧道开挖引起有桩侧向洞内的水平位移远小于无桩侧，且随着桩长增加，这一差异增大。（3）地铁开挖引起短桩以刚性倾斜为主的变位，引起长桩以挠曲为主的变位。（4）地铁开挖对洞周桩土的变形影响可分为4个不同影响区，A区桩土主要以整体下沉变形为主；B区以明显的不对称变形为主要特点，且在桩底会产生一定的压缩刺入变形，沉降量较其余三个区均大；C区特点与B区相似，但沉降量明显减小；D区几乎不受开挖影响。对洞周土体进行了分区，总结了桩端在不同区内时对周围土体位移及桩变形的影响规律，为评定地铁建设对于周围环境的影响提供参考依据。
关键词：地铁；隧道；单桩；数值分析；土体位移变化；桩的变形

Numerical study on subway tunneling-induced pile-foundation deformations

Li Ning^1,2　Wang Zhu¹　Han Xuan^1,3　Liu Houxiang¹
（1. Xi’an University of Technology, Xi’an 710048, China；2.Cold and Arid Environmental
and Engineering Research Institute, the Chinese Academy of Sciences, Lanzhou 730000, China；
3. Beijing Geotechnical Institute, Beijing 100038, China）

Abstract: Numerical analysis is performed to study the features of ground and pile deformations caused by tunneling in the vicinity. The influences of pile position and soil—pile interaction are considered, and the numerical results indicate: 1) The induced ground settlement at the near-tunnel side of the pile is much smaller than that at the other side of the pile, which might cause unbalanced frictions on the pile shaft; 2) The ground horizontal movement around the tunnel is unsymmetric, due to the stiffness effect of the pile; 3) For short piles, tilting is the major form of pile deformation, while for long piles, bending is the major form of pile deformation, as effected by nearby tunneling; 4) Based on deformation behavior, the surrounding soil of the tunnel is categorized into four different zones, to understand better the influence of tunneling to nearby pile foundations.
Keywords: subway；tunnel；single pile；numerical analysis；soil movement；pile deformation
E-mail: ningli@xaut.edu.cn

盾构法隧道开挖面极限支护压力研究

黄正荣^1,2 朱 伟¹ 梁精华¹ 秦建设¹
（1. 河海大学，江苏南京210098；2. 苏州交通设计研究院有限责任公司，江苏苏州215000）

摘要：盾构法隧道施工中，通过在开挖面施加与原始地应力相等的支护压力来预防开挖引起地层变位较大或开挖面失稳，但是由于地层条件和施工等因素的影响，使得开挖面支护压力的设定和控制较为困难，合理的确定开挖面支护压力是盾构掘进施工中一项关键技术,开挖面支护压力大小的控制应该保证不至于压力过低发生开挖面坍塌，同时又不能压力过大而发生隆起破坏，因此目前开挖面支护压力研究中很大部分研究侧重于开挖面极限支护压力的确定。随着计算机技术的发展，数值模拟计算可以模拟盾构法复杂的地下开挖施工过程。文章采用数值模拟方法，研究了地下水位和土层参数对开挖面极限支护压力的影响，给出了合理的开挖面支护压力，并结合一工程实例进行了分析，得出了一些有用的结论，对盾构法隧道施工中合理的确定支护压力的大小具有一定的指导作用。
关键词：盾构隧道；开挖面；数值解；支护压力

A study on the limit support pressure at excavation face of shield tunneling

Huang Zhengrong^1,2　Zhu Wei¹　Liang Jinghua¹　Qin Jianshe¹
（1.Hohai University, Nanjing 210098, China；
2. Suzhou Design & Research Insititute of Communication Co.,LTD, Suzhou 215000, China）

Abstract: During the construction of shield tunnels, support pressure is usually applied at the work face to prevent excessive tunneling-induced soil movement or collapse. However, the selection and control of appropriate support pressure is difficult due to variation of soil conditions and uncertainty in construction. Support pressure should be controlled so that it is not so low as to cause face collapse and not so high as to induce ground hogging.　 Numerical simulation is employed to study how the soil parameter and ground water affect the support pressure, and to give the proper support pressure at the excavation face in a case study.
Keywords: shield tunnel; excavation face; numerical solution; support pressure
E-mail: hhyjs2000@163.com

基于万维网的工程项目管理系统综述

马智亮 罗小春 李志新
（清华大学，北京 100084）

摘要：阐述基于万维网的工程项目管理系统（WPMS）在国内外的发展现状和趋势，以便为结合我国实际情况的WPMS的研制奠定基础。主要通过大量文献调研，对调研结果进行分析、对比、归纳和总结。从WPMS产生、演化和定义、基本架构、关键技术及功能等方面进行了总结和归纳，并使用美国Autodesk公司的Buzzsaw、美国BuildOnline公司的 ProjectsOnline以及作者等研制的EPIMS等典型系统作为例子进行了说明。在此基础上，阐述WPMS的发展趋势为：支持工程项目施工阶段多参与方之间高效的图档管理，支持多参与方对照片及视频的高效管理和便捷应用，以及支持多参与方对已有项目信息资源的开发和利用。上述结果对研制结合我国实际情况的WPMS具有参考和借鉴价值。
关键词：万维网；工程项目管理；管理系统；协同工作；WPMS

Review of web-based project management system

Ma Zhiliang Luo Xiaochun Li Zhixin
(Tsinghua University, Beijing 100084, China)

Abstract: State-of-the-art and tendency of Web-Based Project information Management Systems (WPMS) were summarized in order to lay a sound foundation for developing a WPMS that fits the condition of China. Large amount of literature were investigated, and related analysis, comparison, classification and summarization were carried out. Regarding to WPMS, the origin, evolution, definition, architecture and key technique were classified and summarized. Three typical systems, including Autodesk’s Buzzsaw, BuildOnline’s ProjectsOnline and the EPIMS developed by the authors, were presented for illustration. Based on the mentioned works, three tendencies of WPMS were summarized: first, it will support the multiple participants in the construction phase to collaborate by using the shop drawings; second, it will support the usage of photos and videos for the collaboration among the multiple parties; and third, it will support the utilization of the project information by the multiple parties.
Keywords: world wide web; project management; management systems; cooperative work; WPMS
E-mail: mazl@tsinghua.edu.cn

基于微粒群算法的工程项目质量、费用和工期综合优化

刘晓峰　 陈通　 张连营
（天津大学，天津 300072）

摘要：进度、费用和质量称为工程项目的三大控制目标，三者之间相互依存、相互影响。工程项目控制的理想状态是同时实现合理的工期、较低的费用和较高的质量。微粒群算法(PSO)是新近出现的一种仿生算法，具有简单容易实现，而且随机搜索的优点，使得搜索不易陷于局部最优。将该算法引入工程项目优化领域，研究工程项目的质量、费用和工期的综合优化问题。系统介绍微粒群算法原理、流程以及算法的改进发展，研究工程项目质量、费用和工期的优化，并建立质量、费用和工期的多目标综合优化模型，介绍应用微粒群算法编码解决工程项目多目标优化的方法步骤。最后，通过一个应用实例，计算表明微粒群算法可以准确快速地解决工程项目多目标优化问题。
关键词：微粒群算法；工程项目优化；质量量化

Application of PSO to multiple-objective project optimization

Liu Xiaofeng　 Chen Tong　 Zhang Lianying
(School of Management, Tianjin University, Tianjin 300072, China)

Abstract: Time, cost and quality, with mutual influence, are the three major control items for project management. The best solution for a project is to achieve high quality with low cost in a proper time limit. The Particle Swarm Optimization (PSO) is an evolutionary computational method, which may be conveniently employed to execute random and global search. The Particle Swarm Optimization (PSO) method is employed to conduct multiple-objective project optimization. After introducing the basic theory of the algorithms, an optimization model is formulated to optimize the quality, cost and time of projects. The numerical example indicates that PSO can accurately and efficiently solve multiple-objective project optimization problems.
Keywords: Particle Swarm Optimization(PSO)；project optimization；quality quantification
E-mail: lxf800703@163.com