国家游泳中心子结构模型往复水平加载试验

钱稼茹¹ 胡晓斌¹ 赵作周¹ 傅学怡² 顾 磊²
（1.清华大学，北京100084；2.中建国际（深圳）设计顾问有限公司，广东深圳518033）

摘要：为研究国家游泳中心“水立方”内墙受力最大部分的抗震性能，而完成了1/3缩比的子结构模型在重力荷载代表值和往复水平力作用下的试验。子结构模型的破坏形态为杆件局部屈曲和杆件母材拉断，破坏的杆件主要位于墙面上；杆端贴板使塑性铰和破坏位置转移至杆件上，避免了杆件与节点连接焊缝的破坏。子结构模型受推和受拉的名义屈服位移角分别为1/127及1/100左右，水平荷载分别为880kN和746kN，为顶部附加重量的1.73倍和1.47倍；加载至水平力为附加重量的2倍以上、顶点位移角为1/50左右，承载力尚未下降，水平位移仍能增大。试验结果表明，子结构模型具有大的承载能力、良好的变形能力和耗能能力。
关键词：国家游泳中心；子结构模型；抗震试验；破坏形态；贴板

Cyclic lateral loading test on a sub-structure model of the National Swimming Center

Qian Jiaru¹ 　Hu Xiaobin¹　 Zhao Zuozhou¹　 Fu Xueyi²　 Gu Lei²
（1. Tsinghua University, Beijing100084, China;
2. China Construction(Shenzhen)Design International, Shenzhen 518033, China）

Abstract: To study the seismic behavior of the heavily loaded part of the internal wall of the National Swimming Center, the so called“Water Cube”, an experiment was conducted on a one-third scaled sub-structure model subjected to representative gravity load and cyclic lateral load. Damage of the sub-structure model are in the forms of local buckling and tension fracturing of the base metal of the structural members, and most of the damaged members are at the wall surfaces. Due to the cover plates welded at member ends, the plastic hinges and the damage locations are away from the connections between the members and the joints, thus brittle failure of the weldments is avoided. The nominal yield top drift ratios of the model under push and pull forces are about 1/127 and 1/100, respectively, and the corresponding strength is in the range between 880kN and 746kN, 1.73 and 1.47 times that of the representative gravity load of the model, respectively. The lateral load is 2 times that of the representative gravity load and the top drift ratio is about 1/50, whereas the strength of the model is less than the maximum strength while the lateral displacement may increase further. The sub-structure model exhibits high load-carrying, deformation and energy dissipation capacities.
Keywords: National Swimming Center；sub-structure model；seismic experiment；damage pattern；cover plate
E-mail: qianjr@mail.tsinghua.edu.cn

双锥型变截面矩形钢管的试验研究及承载力分析

罗尧治¹ 张 冰¹ 季伟捷¹ 董石麟¹ 傅学怡² 顾 磊²
（1.浙江大学空间结构研究中心，浙江杭州310027；
2.中建国际（深圳）设计顾问有限公司，广东深圳518033）

摘要: 双锥型变截面矩形钢管是指两端为锥型变截面、中间为等截面的组合矩形钢管构件。首先推导双锥型变截面矩形钢管的强度最不利破坏截面位置的判断公式，阐述双锥型变截面矩形钢管在压弯和压弯扭试验中不同加载方式下试件的破坏模式、塑性区发展过程及承载力结果，并结合大量有限元模型分析，进行不同弯压比下构件承载能力的比较。研究表明，双锥型变截面矩形钢管与等截面构件相比，在弯矩作用下具有更高的承载力，且塑性铰位置避开构件端节点，使整体结构延性得到增强。
关键词：双锥型变截面；矩形钢管；试验研究；承载力；破坏位置；塑性区

Experimental study and capacity analysis of double-tapered rectangular steel tubes

Luo Yaozhi¹　 Zhang Bing¹　 Ji Weijie¹　 Dong Shiling¹　 Fu Xueyi²　 Gu Lei²
(1.Space Structures Research Center, Zhejiang University, Hangzhou 310027, China;
2.China Construction (Shenzhen) Design International, Shenzhen 518033, China)

Abstract: Double-tapered rectangular steel tubes are composed of two tapered ends and a prismatic intermediate part. In this article, the formulas for determining the failure location of the double-tapered tubes are derived. Failure pattern, spreading of plastic zone and bearing capacity of double-tapered tubes are investigated under axial-flexural and axial-flexural-torsional loading experiments. Studies on the bearing capacity of members with different geometric parameters are carried out via FE model analyses. Investigations indicate that the bearing capacity of tubes is notably improved with two tapered ends, and the ductility of the whole structure can also be improved when plastic hinges do not occur at the nodal ends.
Keywords: double-tapered；rectangular steel tube；experimental study；bearing capacity；failure position；plastic hinge
E-mail: luoyz@zju.edu.cn

方钢管混凝土柱-钢梁外加强环节点滞回性能的实验研究

王文达¹　 韩林海²　 游经团¹
（1. 福州大学，福建福州350002；2. 清华大学，北京100084）

摘要：进行了8个方钢管混凝土柱-钢梁外加强环式节点试件在恒定轴力和水平往复荷载作用下的滞回性能实验研究，考察了钢管混凝土柱轴压比和环板宽度对节点力学性能的影响。结果表明：柱轴压比对节点的水平承载力和抗震性能影响较大，随着轴压比的增大，节点的水平极限承载力下降，位移延性和耗能能力降低；不同环板宽度节点的滞回曲线均为饱满的梭形，强度和刚度退化不明显；本次试验的8个节点试件的层间位移延性系数μ=3.00~7.41，弹性极限位移角θy≈2.03[θe]~5.30[θe]，弹塑性极限位移角θu≈1.78[θp]~3.90[θp]，等效黏滞阻尼系数he=0.3576~0.5339，均满足抗震设计要求。
关键词：方钢管混凝土；加强环式节点；抗震性能；延性；耗能

Experimental studies on hysteretic behaviors of steel beam to concrete
filled SHS column connections with stiffening ring

Wang Wenda¹　 Han Linhai²　 You Jingtuan¹
(1. Fuzhou University，Fuzhou 350002，China；2. Tsinghua University，Beijing 100084，China)

Abstract: Eight specimens of steel beam to concrete filled SHS（Square Hollow Section）column connections stiffened by outside rings were experimentally studied on the hysteretic behavior under combined constant axial load and cyclically lateral load. The axial load level of the concrete filled SHS columns and the width of the joint stiffening rings are considered as the experimental parameters of their seismic behavior. The results show that the axial load level of the column has　 an　 obvious effect on both the strength and seismic behavior of the connections.　 With the increase in axial load　 on the columns, the lateral ultimate strength of the connections become lower, and the ductility　 in displacement and the capacity of energy dissipation also decrease. The lateral load（P）versus lateral displacement(Δ) hysteretic curves of all the specimens with different width of outside stiffening rings are of a plump shuttle shape. The curves show no obvious strength deterioration and stiffness degradation. The story drift ductility index μ fluctuates between 3.00 and 7.41, the elastic limit of story drift angle 　θy　 between 2.03［θe］and 5.30［θe］，the elastic-plastic limit of story drift angle　θu between 1.78［θp］and 3.90［θp］, and the equivalent damper coefficient he between 0.3576 and 0.5339. It can be concluded that the tested connections in the study demonstrate good seismic performance.
Keywords: concrete filled SHS column；connections with stiffening ring；seismic behavior；ductility；energy dissipation
E-mail: wangwd@lut.cn

混凝土楼板对钢框架梁柱节点抗震性能影响的试验研究

石永久 苏 迪 王元清
（清华大学，北京100084）

摘要：为了研究节点区混凝土楼板对钢框架梁柱节点抗震性能的影响，完成了4个不同构造形式的节点试件在低周循环荷载下的破坏试验，分析了节点构造与混凝土楼板配筋率等因素对节点承载力、转动刚度、极限转动能力、耗能能力、延性和极限破坏状态的影响。对节点破坏模式和滞回曲线的分析表明，保证焊接质量是避免节点脆性破坏的重要措施。采用长焊接孔的节点，使钢梁发生了局部屈曲破坏，既可减少局部应力集中，又可提高节点的延性，提高配筋率可以显著增强节点的抗弯承载力。另外，混凝土楼板的存在使节点在构造上存在不对称性，应该在节点设计中给予考虑。
关键词：框架节点；楼板组合作用；循环荷载试验；抗震性能

An experimental study on the seismic performance of beam-column joints
in steel frames with the effect of concrete slabs considered

Shi Yongjiu 　Su Di 　Wang Yuanqing
（Tsinghua University, Beijing 100084, China）

Abstract: The effect of concrete slabs on the seismic performance of beam-column joints of steel frames is examined through a series of cyclic loading experiments. Four beam-column joints with floor slabs were tested. The influences of joint details and reinforcement ratios on the load-carrying property, such as rotational stiffness and capacity, energy dissipation capacity, ductility and ultimate failure modes, were thoroughly assessed. From the experimental results, it is found that welding quality is the most important factor for joint ductility. The beam-column joints constructed with proper details and high reinforcement ratios exhibit excellent performance in both bending resistance and energy dissipation under cyclic loads. For those joints with long access holes failed by local buckling, the local stress concentration is reduced while the ductility is improved. Resistance and stiffness of joints increase with the increasing of slab reinforcement. It is found that the unsymmetrical profile of joints due to the existence of concrete slabs should be considered in joint design.
Keywords: joints of frame；composite effect；cyclic loading experiment；seismic performance
E-mail: shiyj@mail.tsinghua.edu.cn

随机变幅疲劳荷载下预应力混凝土梁疲劳寿命的试验研究

冯秀峰^1,2 宋玉普¹ 朱美春³
（1. 大连理工大学海岸和近海工程国家重点实验室，辽宁大连116024；
2. 青岛市国土资源和房屋管理局，山东青岛266002；3. 中国海洋大学，山东青岛266071）

摘要：基于实测的钢筋混凝土吊车梁疲劳荷载谱，经过适当的简化得到试验用随机变幅疲劳荷载谱，并通过MTS疲劳试验机实现了该随机变幅疲劳荷载谱作用下部分预应力混凝土梁的疲劳试验。试验结果表明，由随机变幅疲劳试验得出的构件疲劳寿命远低于由疲劳荷载上限值取为荷载谱均值的等幅疲劳试验得出的疲劳寿命，因此如果采用后者的试验结果去估算实际服役中的预应力混凝土构件的疲劳寿命是非常危险的。然后分别利用Miner准则、相对Miner准则和Corten-Dolan累积损伤准则对承受随机变幅疲劳荷载作用的试件疲劳寿命进行了估算。计算结果表明，改进的Corten-Dolan累积损伤准则精度最高，相对Miner准则也具有较高的精度，Miner准则的精度最低且偏于不安全。建议对预应力混凝土受弯构件进行随机变幅疲劳分析时采用改进的Corten-Dolan累积损伤准则或相对Miner准则。
关键词：预应力混凝土梁；疲劳寿命；随机变幅；寿命估算

An experimental study on the fatigue life of prestressed concrete
beams under random-amplitude fatigue loading

Feng Xiufeng^1,2 　Song Yupu¹ 　Zhu Meichun³
（1. State Key Lab. of Coastal and Offshore Eng., Dalian Univ. of Technology, Dalian 116024, China;2. Bureau of Land Resources and Housing Administration of Qingdao, Qingdao266002, China;3. Ocean Univ. of China, Qingdao 266071, China）

Abstract: Based on the fatigue loading spectrum of R.C. crane beams, established through a practical survey, a random-amplitude fatigue loading spectrum for conducting tests is obtained through appropriate simplifications. Fatigue tests of prestressed concrete beams under the random-amplitude fatigue loading spectrum are conducted by using MTS fatigue machines. The experimental results suggest that the fatigue lives obtained from the random-amplitude fatigue tests are far lower than those obtained from constant-amplitude fatigue tests with the upper values of fatigue loading assumes the mean value of the loading spectrum.　 Thus it is dangerous to use the experimental results from the latter to estimate the fatigue life of prestressed concrete beams in service. The Miner rule, the relative Miner rule, and the Corten-Dolan cumulative damage rule are applied to calculate the fatigue lives of specimens under random-amplitude fatigue loading. Comparisons between the calculated and the experimental results show that the modified Corten-Dolan cumulative damage rule can accurately predict the fatigue lives of specimens. The relative Miner rule can also provide certain accuracy, whereas the results from the Miner rule are considerably unsafe. It is suggested that the modified Corten-Dolan cumulative damage rule or the relative Miner rule be used in estimating the fatigue life of prestressed concrete beams under random-amplitude fatigue loading.
Keywords: prestressed concrete beam；fatigue life；random-amplitude；life estimation
E-mail: fengxiufeng@163.com

混凝土对流换热系数的风洞实验研究

张建荣　　 刘照球
（同济大学，上海 200092）

摘要：提出混凝土表面对流换热系数的实验方案，试件的形式为圆管，从内部加热，安装在TJ-1风洞内，圆管的轴线与风向一致，风速调节范围为1m/s至25m/s，利用专门开发的实验控制系统全自动监控加热过程并自动记录数据。3个试件的实验结果有很好的一致性。实验结果表明，混凝土表面对流换热系数与风速、混凝土表面热辐射系数与温差之间均有很好的线性相关性。由实验结果回归分析得到混凝土表面受迫对流换热系数、混凝土表面热辐射系数、混凝土表面总热交换系数的计算公式，为混凝土结构温度效应分析中热工参数取值提供了依据。
关键词：对流换热；混凝土；风速；温度

A study on the convective heat transfer coefficient of concrete in wind tunnel experiment

Zhang Jianrong　　 Liu Zhaoqiu
（Tongji University, Shanghai 200092, China）

Abstract: An experimental method is developed for measuring the convective heat transfer coefficient of concrete surface. The test specimen is in the form of a circular tube, heated from inside, and installed longitudinally in a TJ-1 wind tunnel.　 The wind speed varies from 1 m/s to 25 m/s, the heating process is controlled and the test data recorded automatically via a specially developed control system.　 The test results of the three concrete tube specimens agree with each other very well.　 There exist linear correlations between the convective heat transfer coefficient of concrete surface and wind speed, the radiation coefficient of concrete surface and the temperature difference.　 The formulae for calculating the convective heat transfer coefficient, the radiation coefficient, and the total heat transfer coefficient of concrete surface are derived based on analyses of the experimental results.
Keywords: convective heat transfer；concrete；wind speed；temperature
E-mail: zhangjr@mail.tongji.edu.cn

基于正交试验的再生骨料混凝土强度研究

李 俊 尹 健 周士琼 李益进
（中南大学，湖南长沙410075）

摘要：研究不同影响因素对再生骨料混凝土强度的影响是再生骨料混凝土研究领域的主要方面之一，对实际工程应用有着重要的意义。采用三因素、三水平的正交试验设计方法对再生骨料混凝土的配合比进行了试验设计，分析了每个因素水平对再生骨料混凝土配合比的作用及各个水平之间的差异，探讨了水胶比、再生骨料掺量、超细粉煤灰掺量等试验因素对再生骨料混凝土强度的影响规律和机理，并与基准混凝土对比。试验结果表明：无论早期与后期，水胶比是影响再生骨料混凝土强度的最主要因素，也是最显著因素；掺粉煤灰再生骨料混凝土的拉压比与同强度等级的高强混凝土相比有所提高，抗裂性能有所改善。采用多元回归分析的方法，建立了再生骨料混凝土强度与水胶比、再生骨料掺量、超细粉煤灰掺量的经验公式。
关键词：再生骨料混凝土; 配合比设计; 正交试验; 强度；回归模型

Study on the strength of recycled aggregate concrete based on orthogonal experiment

Li Jun 　Yin Jian 　Zhou Shiqiong 　Li Yijin
（Central South University, Changsha 410075, China）

Abstract: An orthogonal experimental design method involving three factors and three factor levels is adopted for the mix design of recycled aggregate concrete(RAC), and the effect of each factor level on mix proportion of RAC and the difference between each factor levels are analyzed. The influence and mechanism of different experimental factor, which includes water-binder ratio, percentage of recycled aggregate and ultra-fine fly ash (UFA) content, on the strength of RAC is studied and compared with normal concrete. The experimental results indicate that water-binder ratio is the most principal and significant influencing factor on the strength of RAC, regardless of age. Compared with the normal concrete, ratio of the splitting tensile strength to the compression strength of recycled aggregate concrete with fly ash is increased, and the cracking resistance improved.　 An empirical relationship among the strength of RAC, the water-binder ratio, the percentage of recycled aggregate and UFA content is proposed by using multivariate regression analysis.
Keywords: recycled aggregate concrete；mix design；orthogonal experiment；strength；regression model
E-mail: csu25135@163.com

刚性杆弦支穹顶实物加载试验研究

陈志华 秦亚丽 赵建波 郭 云 窦开亮 李 阳
（天津大学，天津 300072）

摘要：介绍了弦支穹顶体系的研究与应用现状，分析了半刚性弦支穹顶结构的优缺点，以半刚性弦支穹顶的概念为基础，以天津博物馆贵宾厅屋盖为工程背景，按照二阶段设计法中第二阶段结构特性提出并设计了刚性杆弦支穹顶结构。设计了实物加载试验方案，对该刚性杆弦支穹顶进行了静载试验研究，得到了刚性杆弦支穹顶结构内力及位移随加载历程的变化规律。分析比较了试验值与理论计算值，表明刚性杆弦支穹顶具有较好的受力性能。对刚性杆弦支穹顶和结构条件相同的天津博物馆多功能厅屋盖单层网壳进行了比较分析，结果表明刚性杆弦支穹顶具有受力性能优越，用钢量少，施工方便和造价低的优点，为其在工程中的进一步推广应用奠定了基础。
关键词：弦支穹顶；刚性杆弦支穹顶；实物加载试验；结构特性；单层网壳

An experimental study on rigid suspendome structures

Chen Zhihua　 Qin Yali Zhao Jianbo　 Guo Yun　 Dou Kailiang　 Li Yang
（Tianjin University, Tianjin 300072, China）

Abstract: State of the art for suspendome research and application is introduced, and the structural performance of suspendome is analyzed. On the basis of half-rigid suspendome, rigid suspendome is proposed according to the two-stage method. The roof of the VIP Hall of Tianjin museum is designed as a rigid suspendome. A loading test plan on the structure is designed and the experimental study is performed under static load. The structural performance, such as deformation and internal force, with loading process are obtained. By comparing the experimental results with theoretical analyses, the rigid suspendome is proved to exhibit a better mechanical performance. The rigid suspendome is compared with a single-layer dome of same geometry, used as the roof of the multi-purpose Hall of the Tianjin museum. The results indicate that the rigid suspendome has a number of advantages, including good structural performance, less steel consumption, convenient construction and low cost.
Keywords: suspendome；rigid suspendome；loading experiment；structural performance；single-layer dome
E-mail: zhchen@tju.edu.cn

高温下钢筋混凝土框架的内力重分布研究

吴 波 何喜洋
（华南理工大学，广东广州510640）

摘要：通过钢筋混凝土框架的火灾全过程分析，初步探讨高温下钢筋混凝土框架的内力重分布规律。推导建立了高温下钢筋混凝土的简化梁单元模型，编制了钢筋混凝土框架高温反应的全过程分析程序，程序的正确性得到了其他学者试验结果的验证。选取1榀单层3跨的钢筋混凝土框架，针对不同梁柱线刚度比和不同柱子轴压比的情况分别进行了该框架的高温反应分析，考察了部分控制截面的内力重分布规律。研究结果表明，高温下框架结构产生剧烈的内力重分布，其中框架梁的轴力和梁端弯矩变化尤为剧烈，成为影响框架结构其他控制截面内力变化的主要因素之一；随着梁柱线刚度比和柱子轴压比增大，框架梁的轴向压力逐渐加大。在结构层次上开展钢筋混凝土框架的耐火研究，可更为全面科学地把握不同构件的最不利受力状况。
关键词：钢筋混凝土；框架；高温；内力重分布

A study on the redistribution of internal forces in reinforced
concrete frames under high temperature

Wu Bo　　 He Xiyang
(South China University of Technology, Guangzhou 510640, China)

Abstract: The redistribution of internal forces in reinforced concrete frames under high temperature is primarily studied. For the study, a simplified beam-element-model for reinforced concrete is employed. An analytical procedure for reinforced concrete frames under high temperature is proposed and the procedure is validated by using the test results found in the literature. A three-span one-storey reinforced concrete frame is selected for fire response analysis. Different line-stiffness-ratios of beam to column and different axial load ratios of column are considered in the analysis. The redistribution of internal forces at some key sections in the frame is discussed in the paper. The analysis results indicate: (1) redistribution of internal forces in the frame subjected to high temperature is quite significant; (2) redistribution of the axial force of the beam and the redistribution of the bending moment at the end of the beam are especially significant, and these are the most important causes of the variations of the internal forces in other sections; and (3) with an increase in the line-stiffness-ratio of beam to column and in the axial load ratio, the axial force of the beam increases accordingly.
Keywords: reinforced concrete；frame；high temperature；redistribution of internal force
E-mail: bowu@scut.edu.cn

带竖缝钢筋混凝土剪力墙板的简化静力分析模型

张耀春 刘永华 丁玉坤 张文元
（哈尔滨工业大学，黑龙江哈尔滨150090）

摘要：带竖缝钢筋混凝土剪力墙板在弹性状态下有较大刚度，而在弹塑性状态下又有较好的延性，是一种抗震性能较好的结构单元。但由于缺少有效的分析模型，带竖缝钢筋混凝土剪力墙板在国内的工程应用很少。根据带竖缝钢筋混凝土剪力墙板的V-u曲线，按照侧向刚度相同的原则将之等效为偏心交叉支撑简化模型，并给出了简化模型的截面特性和材料本构关系曲线。通过算例统计分析给出了偏心距的取值范围及简化分析模型的适用范围。与更接近于实际墙板特性的等效带竖缝板模型的算例对比分析表明，在框架结构静力分析中采用简化模型模拟带竖缝钢筋混凝土剪力墙板是可行的。
关键词：带竖缝钢筋混凝土剪力墙板；静力分析；偏心交叉支撑简化模型；延性；抗震性能

A simplified model for static analysis of slit RC shear walls

Zhang Yaochun　　 Liu Yonghua　　 Ding Yukun　　 Zhang Wenyuan
（Harbin Institute of Technology, Harbin 150090, China）

Abstract: Slit RC shear walls, which have appropriately large lateral stiffness in elastic state and good ductility in inelastic state, may serve as desirable aseismic structural members. However, there are few applications of slit RC shear walls in China due to lacking an effective model for global structural analysis. A simplified model, i.e., an eccentric cross-bracing model, is proposed to represent the structural actions of the slit RC shear wall in a global analysis. The model is established on the basis of an equivalent lateral stiffness according to the shear force versus lateral deflection curve of the slit RC shear walls. Both section characteristics and material constitutive curve of the simplified model are introduced. Numerical examples involving both the simplified model and a more accurate model, named the equivalent slit panel model, are presented to demonstrate the accuracy of the simplified model. According to the statistical results of the numerical examples, the range of brace eccentricity and the applicability of the simplified model are identified. Numerical results indicate that the simplified model of a slit RC shear wall can be effectively utilized for the global static analysis of frame structures.
Keywords: slit RC shear wall; static analysis; simplified eccentric cross-bracing model; ductility; aseismic behavior
E-mail: jxln753@163.com

钢管混凝土拱桥的动力稳定极限承载力研究

徐　 艳　 胡世德
（同济大学，上海200092）

摘要：从结构极限承载力的角度研究钢管混凝土拱桥在地震作用下的动力稳定性能。基于大型通用有限元程序ANSYS的应用平台，使用其APDL语言，采用 B-R运动准则结合动态增量法（IDA）提出用特征响应寻求钢管混凝土拱桥动力稳定极限承载力的研究方法，分析地震动输入方向、结构几何非线性、材料非线性及其结构初始缺陷模式和大小对动力稳定极限承载力的影响，结果表明横向输入对拱桥稳定最为不利，材料非线性的影响比几何非线性影响大，几何初始缺陷会降低拱桥的动力稳定极限承载力，其中以反对称最为不利。最后，通过对一钢管混凝土模型拱桥的振动台试验的分析比较，表明该方法的正确性和工程适用性，可为系统研究钢管混凝土拱桥的动力稳定性能提供理论分析基础。
关键词：钢管混凝土拱桥；非线性；动态增量法；初始缺陷；动力极限承载力

A study on the dynamic ultimate capacity of CFST arch bridges

Xu Yan　 Hu Shide
(Tongji University，Shanghai 200092，China)

Abstract: The dynamic stability of concrete filled steel tubular(CFST)arch bridges under earthquakes is studied with respect to the structural ultimate bearing capacity. Based on the finite element software package(ANSYS), a method for using representative responses to study the dynamic ultimate capacity of CFST arch bridges is proposed by application of Incremental Dynamic Analysis in combination with the B-R dynamic criteria. The influence factors, such as earthquake input directions, geometric and material non-linearities, and the initial imperfection modes and magnitudes, are investigated. The results indicate that the bridge is affected the most by lateral earthquake input, that material non-linearity has a more serious effect than geometric non-linearity, and that the initial imperfection reduces the ultimate capacity, and the anti-symmetrical mode might be the worst case. The method is compared with a CFST model arch shaking table test, the result of which indicates that the method proposed is correct and applicable in engineering practice.
Keywords: CFST arch bridge; nonlinear; incremental dynamic analysis; dynamic ultimate capacity
E-mail: helen_xuyan@hotmail.com

大跨度斜拉桥拉索安全性分析方法研究

朱劲松¹ 肖汝诚²
（1.天津大学，天津300072；2.同济大学，上海200092）

摘要：斜拉桥的斜拉索在运营期间的安全是斜拉桥结构安全的最重要条件之一，对斜拉索安全性的分析显得至关重要。考虑构成平行钢丝束斜拉索的高强钢丝本构行为的不均匀性和钢丝之间的相互影响，将Matteo的钢丝延脆性模型和Monte Carlo仿真方法相结合，建立斜拉索的强度模型，并从可靠度观点出发分析了斜拉索在桥梁运营条件下安全系数的变异和演化特性，并提出断丝率随服务期演化的线性经验公式来描述拉索的退化问题。在此基础上提出了大跨度斜拉桥拉索安全性分析的工程方法，并以招宝山大桥最长索为例，详细阐述了分析过程，该方法为斜拉桥拉索的安全评估与剩余寿命估算提供了依据。
关键词：斜拉桥；拉索；评估；安全系数；蒙特卡罗法

A study on the safety assessment method for stay cables of long-span cable-stayed bridges

Zhu Jinsong¹　　 Xiao Rucheng²
（1.Tianjin University, Tianjin 300072, China; 2.Tongji University, Shanghai 200092, China）

Abstract: Stayed cables are primary members for cable-stayed bridges. The safety assessment of stayed cables is a key issue to the safety of the structures.　 Some recently developed models for strength assessment of stayed cables are presented and illustrated.　 These models are based on the Matteo’s ductile-brittle wire model and the Monte Carlo simulation. A linear equation is proposed for simulating the deterioration of the cables，and a safety assessment method for stay cables of long-span cable-stayed bridges is proposed. Application to the Zhao Bao Shan cable-stayed bridge in China is made by taking into account the tensile test results and the empirical data obtained from the design and cable force inspection of the stayed cables. The analysis of the longest cable is illustrated, and the results indicate that the proposed method could be used to assess the safety and residual life of stayed cables in cable-stayed bridges.
Keywords: cable-stayed bridge; cable; assessment; safety factor; Monte Carlo method
E-mail: zhu.jinsong@163.com

数值模拟联合算法及其在润扬大桥可靠度评估中的应用

郭 彤 李爱群 缪长青 费庆国
（东南大学，江苏南京210096）

摘要：为了定量研究大跨桥梁在外界随机因素作用下的结构安全性，实现在线状态的可靠度评估，利用可靠度的随机有限元法对润扬大桥悬索桥在正常运营和损伤等多种工况下的结构可靠度进行了数值模拟和可靠度评估。分析中采用蒙特卡罗重要抽样法和中心复合响应面法的联合算法作为数值模拟的基本工具，介绍了联合算法的具体实现途径、随机变量的参数定义并对大跨桥梁基于可靠度指标的评估准则进行了讨论。得到了多个随机变量的概率灵敏度、主要失效模式所对应的可靠度指标及其相应的状态等级。算例分析结果表明，基于随机有限元的可靠度分析方法可以较好地描述大跨桥梁的非线性特征，联合算法的应用提高了可靠度分析的效率和精度，其结果为润扬大桥悬索桥的状态评估和健康监测提供了参考。
关键词：可靠度；蒙特卡罗法；响应面法；状态评估；健康监测

Combined numerical simulation method and its application on the
reliability assessment of the Runyang Bridge

Guo Tong　 Li Aiqun　 Miao Changqing　 Fei qingguo
(Southeast University, Nanjing 210096, China)

Abstract: To obtain the reliability of long span bridges under the influence of external random factors and to realize the online condition assessment, numerical simulation and reliability assessment of the Runyang Suspension Bridge is conducted by using the stochastic finite element method (SFEM). The Monte Carlo Importance Sampling method and the Central Composition Response Surface method are combined as the basic tool of numerical simulation. The definition of random factors, the application of the combined method and the assessment criterion based on reliability index are introduced and discussed. The probability sensitivities between random variables are analyzed and the reliability index and the corresponding condition classes are obtained. Examples indicate that the reliability analysis using SFEM can describe the nonlinearity of long span bridges and the combined method can increase the efficiency and accuracy of reliability analysis.
Keywords: reliability; Monte Carlo method; Response Surface method; condition assessment; health monitoring
E-mail: civilcenter@163.com

土压平衡盾构掘进的数学物理模型及各参数间关系研究

王洪新^1,2　傅德明²
（1.同济大学，上海200092；2.上海隧道工程股份有限公司，上海200082）

摘要：为保证开挖面稳定及控制地面沉降，土压平衡盾构掘进时必须合理匹配各施工参数。基于模型试验结果，推导土压平衡盾构的3个基本方程式，进而得到土压平衡盾构2个总平衡方程式，建立土压平衡盾构掘进的数理模型。在此基础上推导总推力、土仓压力、螺旋机转速、掘进速度间关系的数学表达式，利用盾构施工的现场数据验证关系式的正确性。利用现场掘进数据统计刀盘扭矩、刀盘转速、土仓压力间的经验关系式。这些关系对土压平衡盾构设计时的参数选择和匹配有重要的指导意义，可以应用于土压平衡盾构施工时的参数控制。土压平衡盾构掘进的连续性方程为土压平衡盾构掘进时的地面沉降控制提供了新的研究思路。
关键词：土压平衡盾构；平衡方程；模型；施工参数；关系

A mathematical model and the related parameters for EPB shield tunneling

Wang Hongxin^1,2　 Fu Deming²
（1. Tongji University, Shanghai 200092, China;
2. Shanghai Tunnel Engineering Co., Ltd., Shanghai 200082, China）

Abstract: For EPB (Earth Pressure Balance) shield tunneling, one must properly choose driving parameters to maintain face stability and control ground subsidence. Based on the data of a model test, three fundamental equations for EPB shields are derived, from which two general balance equations are developed, to form a mathematical model of EPB shield tunneling. The theoretical relationships between total thrust, in-chamber earth pressure, rotation speed of screw conveyor and advancement rate are established and validated by field data. Empirical relationships between cutter-head torque, cutter-head rotation speed and earth pressure in the chamber are thus obtained.
Keywords: EPB shield; balance equation; model; parameter; relationship
E-mail: tjwanghongxin@sina.com

大规模桩筏基础非线性共同作用简化分析方法

孙晓立 杨 敏
（同济大学，上海 200092）

摘要：提出一种分析桩筏基础非线性共同作用的简化分析方法。将单桩的载荷试验结果应用到桩筏基础的沉降分析中，从而使得沉降预测结果更符合工程实际情况。将筏板假定为弹性薄板，筏板下的群桩假定为相互作用的非线性弹簧，使用双曲线函数拟合载荷试验的Q-S曲线，并用它来模拟桩在荷载下的非线性响应。采用相互作用系数法分析桩-桩间的相互作用，同时考虑桩的“加筋”对相互作用系数的影响。为了简化计算，采用多项式拟合桩-桩、桩-土相互作用系数。使用弹性半空间或有限层理论分析土节点间的相互作用。经过实例分析比较，该方法不但可以节省大量机时，而且可以得到较满意的预测结果。该简化方法可以用于工程实践。
关键词：桩筏基础; 相互作用系数; 非线性

A simplified method for the analysis of the nonlinear interaction of large scale piled rafts

Sun Xiaoli　　 Yang Min
（Tongji University，Shanghai 200092，China）

Abstract: A simple method is proposed for the analysis of the nonlinear interaction of large piled rafts. The simple method involves applying single pile load test result to the settlement of piled rafts. The raft is modeled as a thin plate and the piles are modeled as interacting nonlinear springs. The Q-S curves from single pile load test can be simulated by a hyperbola function, which can be employed to model the non-linear characteristics of the piles. The interaction between piles is analyzed by using interaction factors, and the‘restraint’action between piles is considered.　 The factors of pile-pile and pile-soil interactions are simulated by using multinomial regressions. The interaction between soil elements can be analyzed by elastic semi-space or finite layer theory. Comparing with the results of the piled raft and the model pile groups, the approximate method can save computing time while gives a　 reasonable results.
Keywords: piled raft；interaction factor；nonlinearity
E-mail: sunxiaoli5428@sina.com

控制冻土融化容许值的建筑物通风管基础计算方法

徐学燕^1,2 　苏万鑫¹　 徐春华¹
（1．哈尔滨工业大学，黑龙江哈尔滨150006；
2．中国科学院兰州寒区旱区环境与工程研究所冻土工程国家重点实验室，甘肃兰州730000）

摘要：根据传热理论，在现有JGJ 118—98《冻土地区建筑地基基础设计规范 》中采用的无通风管基础的冻土地基的最大融化深度的计算公式基础上，推导出有通风管基础按容许地基土逐渐融化原则设计的冻土地基最大融化深度的计算公式，首次提出了等效地面温度和等效地面温度系数的概念。首次建立室内采暖条件下通风管复合基础的传热数学模型，并在此模型基础上采用有限单元法对通风管复合基础进行数值模拟分析结合理论推导的方法，得出不同室内地面温度、不同通风管间距时的通风管基础中心下的温度沿深度分布曲线及54个等效地面温度数据，依据最小二乘法原理对以上数据拟合出工程广泛采用的通风管直径为300 mm的通风管基础的等效地面温度系数计算公式，从而提出建筑物通风管基础通风面积计算方法，由实际工程设计验证了该计算方法的可靠性与实用性。
关键词：多年冻土；通风管基础；等效地面温度系数；通风管通风面积

An approach for computing the ventilated foundation of buildings based on controlling the permissible value of permafrost thawing

Xu Xueyan^1,2　 Su Wanxin¹　 Xu Chunhua¹
(1.Harbin Institute of Technology, Harbin 150006, China; 2. State Key laboratory of frozen Soil Engineering, CAREERI, CAS, Lanzhou 730000, China)

Abstract: Based on the heat-transfer theory, a calculation formula is derived for the maximum thawing depth of frozen ground under ventilated foundations. From the design viewpoint in allowing gradual thawing of the foundation soil, both the concept of equivalent floor temperature and the associated temperature coefficient are presented. Through theoretical analysis and numerical simulation, 54 equivalent floor temperatures and the temperature distribution curves with depths are obtained for different inner floor temperatures and spaces between vent-pipes. The calculation method for the equivalent floor temperature factor of ventilated foundations with vent-pipes of a 300mm diameter is obtained by using a compound foundation model and the method of least squares. The design method for areas of ducts that control the permissible value of permafrost thawing is obtained. The reliability and practicability of the calculation method is validated in practical engineering designs.
Keywords: permafrost; ventilated foundation; equivalent floor temperature coefficient; ventilating area
E-mail: xuxueyan_hit@sina.com

水泥土桩复合地基荷载传递及变形的原位试验研究

马海龙
（浙江理工大学，浙江杭州310018）

摘要：为了获得桩长、置换率等对水泥土桩复合地基荷载传递及变形的定量影响，在5组4桩群桩和5组9桩群桩复合地基的桩体内埋设应变计，在桩间土体内埋设深层沉降标，实测到4桩群桩和9桩群桩复合地基中桩体轴力分布、桩侧摩阻力分布和桩间土变形分布。发现置换率相同时，承台板宽度大，水泥土桩的荷载临界深度也大，桩侧摩阻力分布深度下移。承台板宽从1.0m增加到1.5m时，荷载临界深度由14倍桩长增加到18倍桩长。变形影响深度约为承台板宽度的（1.8~2.5）倍。最大摩阻力出现在承台下1.5m处，该处的竖向偏应力最大，桩体容易在这里破坏。增加桩长能有效减少沉降。荷载水平达到70%以后，变形影响深度下移不再明显。
关键词：水泥土桩；原位试验；荷载传递；荷载临界深度；荷载水平

Field test on the load transfer and deformation of cement-soil pile group
Ma Hailong

（Zhejiang Sci-Tec University, Hangzhou 310018,China）

Abstract: To obtain the quantitative influence of pile length and replacement ratio on the load transfer and displacement of cement-soil pile groups, strain gauges were mounted on the cement-soil piles and deep settlement instruments buried in the soil, for a total of five 4-pile groups and five 9-pile groups. The axial force along the pile shaft, the skin friction and the soil settlement were measured. It is found that the load critical depth and the friction range increase while the cap breadth increases with the same replacement ratio. The load critical depth changes from 14 to 18 times of the pile diameter while the cap breadth varies from 1.0m to 1.5m. The deformation influence depth is about 1.8 to 2.5 times the cap breadth. The maximum friction occurs at about 6 times of the pile diameter（1.5 m） beneath the cap. Long pile can significantly reduce the settlement. However, the deformation influence depth does not increase when the load-level is equal to or exceeds 70%.
Keywords: cement stabilized soil pile; test in situ; load transfer; load critical depth; load-level
E-mail: ma-hailong@163.com

BAYES方法在房地产项目方案比选中的应用

温海珍¹　 贾生华¹　 杨志威²
（1. 浙江大学，浙江杭州 310027；2. 香港理工大学， 中国香港）

摘要：房地产项目方案的选择是房地产开发过程中重要的决策问题之一，在不确定性环境下利用贝叶斯方法进行方案选择，并对黄山市屯溪新城项目进行了实证研究。采用访谈法和专家打分法，从黄山市房地产市场的8个影响因素中总结出两个关键因素：徽杭高速公路的建设进程，黄山市屯溪区城市发展进程。利用贝叶斯方法，计算了4种外部环境下项目方案的期望收益和16个决策函数的贝叶斯收益值，发现多层公寓的市场需求主要是本地需求，别墅的本地需求较小，但是徽杭高速公路的顺利开通可以促进别墅市场的需求。实证分析同时表明，贝叶斯方法可以有效地进行房地产项目方案的选择，有利于减少项目开发的前期风险。
关键词：不确定性；方案比选；贝叶斯决策

Application of the Bayesian method on the selection of real estate projects

Wen Haizhen¹　 Jia Shenghua¹　 Yang Zhiwei²
（1. Zhejiang University, Hangzhou 310027,China；
2. The Hong Kong Polytechnic University, Hong Kong, China)

Abstract: Project selection is an important decision-making issue in real estate development. The Bayesian method is applied for project selection under uncertain circumstances, and a Tunxi New Town project in Huangshan City is employed as a case study. Through interview and scoring by expets in the area, two key factors, the progress of the Huihang highway construction and the urban development process of the Tunxi district of Huangshan City, are identified. The Bayesian method is applied to calculating the expected project returns in four circumstances and the Bayesian earnings of 16 decision-making functions. The major conclusions are: for multi-story apartment market, housing demand is mainly local; for villa market, the local demand is smaller, but, with the completion of the Huihang highway, the villa market will be promoted. Empirical analysis also shows that the Bayesian method can effectively facilitate the selection of real estate projects and reduce early-stage risks of project developments.
Keywords: uncertainty；project selection；Bayesian decision
E-mail: wenhaizhen@263.net

正交异性钢桥面铺装层疲劳寿命的断裂力学分析

黄 卫¹ 林广平¹ 钱振东¹ 刘振清²
（1. 东南大学，江苏南京210096；2. 交通部公路科学研究所，北京100088）

摘要：计算和分析正交异性钢桥面铺装层表面裂缝应力强度因子，在此基础上应用Paris扩展公式预测铺装层疲劳寿命。将奇异单元布置在铺装层表面裂缝前沿，建立正交异性钢桥面系三维断裂力学有限元模型，计算铺装层表面裂缝的应力强度因子；分析裂缝应力强度因子随轴载作用位置的变化规律，确定了带裂缝铺装层轴载作用的最不利荷位；以最不利荷位作为轴载作用的标准荷位，计算应力强度因子随裂缝扩展深度的变化，并数值拟合得到了应力强度因子与裂缝深度的关系式；将应力强度因子的深度关系式代入Paris公式，积分得到铺装层的疲劳寿命。计算结果表明，基于钢桥面铺装层带裂缝工作的事实，应用断裂力学方法预测钢桥面铺装层疲劳寿命是可行的。
关键词：正交异性钢桥面板；钢桥面铺装；断裂力学；应力强度因子；Paris公式；疲劳寿命

Fracture-mechanics analysis of the fatigue life of the
pavement on orthotropic steel bridge decks

Huang Wei¹　　 Lin Guangping¹　　 Qian Zhendong¹　　 Liu Zhenqing²
（1.South-east university, Nanjing 210096, China；
2.Research Institute of Highway, Ministry of Communications, Beijing 100088, China）

Abstract: The stress intensity factor (SIF) for the surface crack of the pavement on orthotropic steel bridge decks is calculated and analyzed. The Paris’formula is employed to forecast the fatigue life of the pavement. A three-dimensional fracture-mechanics finite element model of orthotropic steel bridge deck systems is developed.　 According to the change in the SIF with the change in the loading position of the axle-load, the worst loading position of the axle-load on the cracking pavement of the steel bridge deck is determined, the change in the SIF with the change in the crack depth is analyzed, and the relationship between the SIF and the crack depth is established. The expression of the SIF is substituted into the Paris’formula, and the fatigue life of the pavement is calculated by using an integral of the Paris’formula. The result indicates that fracture mechanics can be employed to forecast the fatigue life of the pavement on orthotropic steel bridge decks.
Keywords: orthotropic steel bridge deck；paving of steel bridge deck；fracture mechanics；stress intensity factor； Paris’formula：fatigue life
Email: lgp215@sohu.com

高速铁路路基动力响应中的双峰现象分析

梁 波^1,2　 孙常新³
（1. 重庆交通大学结构工程重点实验室，重庆400074；
2. 兰州交通大学，甘肃兰州730070；3. 华北水利水电学院，河南郑州450008）

摘要：结合我国高速客运专线铁路的发展形势，着重分析时速超过200 km/h以上的路基动力响应。采用能够综合反映车辆和轨下基础因素的模拟振动荷载，通过非线性数值分析，研究了高速行车条件下路基动力响应包括横断面位移、加速度、应力随行车速度的突变或双峰现象的变化规律，探讨了路基设计参数与双峰现象的关系，并与部分实测结果进行了对比分析。还初步研究了引起这一现象的不平顺和体系共振等因素在不同车速范围的作用程度。路基动力响应的双峰现象表明，车辆和轨道基础之间存在着复杂的相互作用，这些作用同时共存，随着条件的变化，此消彼长。通过这一分析，为进一步认识高速铁路路基的动力特性和进行高速铁路轨下基础设计提供了参考。　　　
关键词：高速铁路；路基；动力响应；双峰现象

A study on the sudden changes or double peaks in the dynamic
response of subgrade of high speed railway

Liang　 Bo^1,2　 Sun Changxin³
（1. Key lab. of Structure Engineering, Chongqing Jiaotong University, Chongqing 400074, China;2. Lanzhou Jiaotong University, Lanzhou 730070, China; 3. North China Institute of Water
Conservancy and Hydroelectric Power, Zhengzhou 450008, China）

Abstract: In connection with the development of special high speed passenger railway-lines in China, the dynamic response of railway subgrades is analyzed for train speeds over 200km/h. Using a simulated dynamic load that suitably reflects the vehicle factor and structural factor below the track and using non-linear numerical analyses, the sudden changes or double peaks are identified in the dynamic response of subgrades under high speed conditions. The study found that factors such as the resonant vibration and line irregularity are the major influence factors in various speed ranges. The calculations are compared with test results.
Keywords: high speed railway; subgrade; dynamic response; double peaks
E-mail: liang_laoshi@126.com

超薄白色罩面（UTW）结构设计方法

李宇峙¹ 崔 鹏² 邵腊庚¹
（1.长沙理工大学，湖南长沙 410076；2.同济大学，上海 200092）

摘要：为了研究半刚性基层沥青路面上超薄白色罩面(UTW)结构设计方法，采用三维有限元方法计算了UTW路面结构的荷载应力。通过计算确定了UTW路面的设计荷位为纵缝边缘中部。基于基层顶面当量回弹模量(Et)和旧沥青层模量(Ea)及统计分析结果，提出结构强度综合系数为Rj=Et (1/3)×log(Ea)，得到了Rj<17时的板厚设计图表，并验证了Rj<17适用于我国大部分需要修复的沥青路面的路况。借鉴水泥混凝土路面设计规范，在考虑疲劳及可靠度的基础上，提出了考虑温度和荷载综合影响的UTW路面结构设计计算公式，并通过足尺试验验证了该设计方法的可行性，同时对确保UTW层间黏结的施工方法进行了探讨。最后探讨了UTW路面结构的适应性，并指出其在重载高等级道路的适用性尚需实体工程进一步验证。
关键词：道路工程；超薄白色罩面；结构强度综合系数；设计方法

Design method for ultra-thin whitetopping (UTW) structures

Li Yuzhi¹　　 Cui Peng²　　 Shao Lageng¹
（1. Changsha University of Science and Technology, Changsha 410076, China;
2. Tongji University, Shanghai 200092, China）

Abstract: In order to investigate the design method for UTW structures on semi-rigid asphalt pavement, a 3-D FE code is employed to calculate the load-induced stresses of a UTW structure. The calculation confirms that the center of the longitudinal joint edge is the design loading position of UTW. Based on an Equivalent Resident Modulus of the top of the base(Et), modulus of existing asphalt layer(Ea) and statistic analysis result, a generalized coefficient of structural strength(Rj) is proposed as, Rj=E t (1/3) ×log(Ea), together with a thickness design chart for Rj<17. It is also validated that the Rj value, if less than 17, is applicable to most asphalt pavements in China that require rehabilitation work. Considering the fatigue and the reliability referencing in the equations of the current cement concrete pavement design specifications, the combined effect of temperature and load on UTW structure for pavement design is calculated and the corresponding design method is validated by a full-scale test. Moreover, the construction method is discussed in the paper to ensure a good interface condition of UTW, and the adaptability of UTW structure is also analyzed. It is pointed out that the adaptability of UTW to heavy-load expressways should be further studied via projects in the field.
Keywords: road engineering; Ultra-thin Whitetopping; general coefficient of structural strength; design method
E-mail: xieshou79@163.com