大型厂房钢筋混凝土框排架结构中异型节点的
抗震性能和设计方法研究

吴 涛¹　 刘伯权¹　 白国良²　 李红星²
（1. 长安大学，陕西西安 710064；2. 西安建筑科技大学，陕西西安 710055）

摘要：针对大型厂房框排架结构中通常存在变梁变柱异型节点的实际情况，进行4个1/5比例异型中节点伪静力试验研究及含有该类节点整体结构的试验，分析大小梁相对刚度、大小核心面积及小核心与柱配箍率等因素对该类节点破坏模式的影响。研究结果表明：该类节点初裂荷载、极限荷载较常规节点显著降低，通裂阶段与极限阶段非常接近，易发生小核心剪切破坏和柱端剪切破坏等两种破坏模式。采用约束机理对小核心剪切破坏进行分析并提出承载力计算方法；对于柱端剪切破坏应采用限制大梁底部纵向钢筋的方法予以避免。提出采用大小梁端弯矩比为参数区分不同类型的破坏模式，为该类异型节点合理设计提供了依据。
关键字：框架异型节点；抗震性能；破坏机理；设计建议

A study on the seismic behavior of and the design method for irregular reinforced concrete frame joints of large-scale plant structures

Wu Tao¹　 Liu Boquan¹　 Bai Guoliang²　 Li Hongxing²
(1.Chang’an University，Xi’an 710064，China；2.Xi’an University of Architecture & Technology，Xi’an 710055，China)

Abstract：Large-scale plants commonly involve irregular structural joints consisting of beams and columns with abrupt cross-sectional changes. Pseudo-static structural tests on four 1/5-scale specimens have been performed and the failure characteristics of these specimens were investigated. The factors affecting failure modes of irregular joints were found to be the stiffness ratio of large beam to small beam，the areas of large core and small core，and the stirrup ratios of small core and column，etc. The experimental results showed that the cracking load and the ultimate load of irregular joints obviously decrease when compared with regular joints，and that the penetrating crack load is very close to the ultimate load. Moreover，two typical failure modes may occur simultaneously，namely，they are the small core shear failure and column shear failure. A constraint mechanism method was employed to express the small core shear failure and an empirical formula for calculating shear-bearing capacity of irregular joints are is thus proposed. The steel ratio at the bottom of a large beam should be restricted to avoid possible column failure in shear. Further，the bending moment ratio of a small beam to large beam may be employed to distinguish the failure modes of irregular joints.
Keywords：irregular frame joint；seismic behavior；mechanism of failure；design proposition
E-mail：wutao760922@163.com

基于无网格伽辽金法的裂缝处理方式

司建辉　 简 政　 李九红
（西安理工大学，陕西西安 710048）

摘要：在介绍目前无网格伽辽金法中模拟裂缝的主要方法的基础上，将有限元中用于模拟裂缝的弥散式裂缝处理方式引入到无网格伽辽金法中，通过修改开裂的高斯点及节点的弹性模量，可方便地模拟裂缝的发生及发展，并编写相应程序，针对受集中力作用的混凝土悬臂梁，进行裂缝的发生、发展分析，得到构件的开裂荷载及极限荷载，其开裂轨迹符合一般开裂发展规律。表明应用无网格伽辽金法结合弥散式裂缝处理方式来处理混凝土构件裂缝的发生、发展是可行的。
关键字：无网格伽辽金法； 弥散式裂缝

Treatment of cracks using an element-free Galerkin method

Si Jianhui　 Jian Zheng　 Li Jiuhong
（Xi’an University of Technology，Xi’an 710048，China）

Abstract：Dispersion treatment of cracks employed in the finite element method is applied to an element-free(or meshless)Galerkin method. By modifying the modulus of elasticity of the cracked elements at the Gauss points，this method can be employed to simulate both the crack initiation and crack growth. Using a in-house developed computer code，the cracking phenomenon of a cantilever beam under a concentrated load is analyzed. The analysis results indicate that the crack path follows a commonly-known propagating pattern. The paper demonstrates that the use of meshless Galerkin method with the dispersion treatment can effectively predict both the cracking load and the ultimate load all together.
Keywords：element-free Galerkin method；dispersion treatment of cracks
E-mail：sjhfr@xaut.edu.cn

超高压输变电钢管构架加固技术的研究与应用

卢亦焱　 张号军　 刘素丽
（武汉大学，湖北武汉 430072）

摘要：通过11根薄壁钢管柱外粘钢板加固后的轴心抗压试验，对超高压输变电钢管构架采用外粘钢板加固后的受力性能进行研究，试验结果表明：外粘钢板能与原钢管有效地联合工作，显著提高原钢管柱的刚度和承载力，增强其稳定性。在试验研究的基础上，通过理论分析，提出外粘钢板加固钢管柱的加固设计方法，推导加固后复合体系整体刚度的计算公式，并采用有限元方法对外粘钢板加固钢管柱的受力性能进行数值模拟分析，进一步验证试验研究和理论分析的正确性。同时结合实际工程应用，提出有效可行的施工方案，解决外粘钢板在构架基础上锚固的问题。研究成果可为大量需要进行加固处理的输变电钢管构架以及其他类似结构工程加固提供参考。
关键词：外粘钢；钢管；加固；输变电构架

Study and application of a reinforcement technique of steel-tube truss for
ultra-high voltage power transmission

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

Abstract：Eleven steel tubular columns strengthened by sticking steel plates(or stiffeners)on the outer surfaces of the columns and these members were tested by axial-compression to determine their structural performances. The test results show that the stiffness，stability and ultimate bearing capacity of the steel pipe columns can be improved greatly due to the combined work between the stiffener and the thin-wall steel tube. Based on the experimental results，the design methods of reinforcement and formulas for the composite structural stiffness were proposed. Furthermore，the finite element method was used to simulate the behavior of steel pipe reinforced by the stiffener，and the experimental measurements appeared to support the analysis performed. An effective technique for construction of plate stiffener connecting with the foundation was also introduced through engineering applications. Present research findings can provide a useful reference for applications to other similar engineering projects.
Keywords：sticking steel plate outside；steel pipe；reinforcement；truss in transformer substation
E-mail：yylu901@163.com

竖向变形差异补偿对结构性能的影响

周绪红¹ 　　黄湘湘² 　　王毅红¹ 　　狄 谨¹ 　　刘永健¹
（1．　长安大学，陕西西安 710064；2. 湖南大学，湖南长沙 410082）

摘要：经过多种补偿方案的比较，提出钢框架－钢筋混凝土核心筒体系竖向变形差异的楼层组优化补偿方案，并研究竖向变形差异补偿对结构的内力和变形的影响。利用有限元程序SAP2000进行结构分析，在分析中分层施加竖向荷载，考虑混凝土收缩和徐变的影响。分析表明，钢框架－钢筋混凝土核心筒体系竖向变形差异楼层组优化补偿方案，既能保证补偿的精度，又经过优化使施工更为方便，是一种比较合理的补偿方案。采用楼层组优化补偿方案可以使楼层的最大累积变形差异明显减小，保证水平构件的水平度。在补偿结构中，只有位于平面四角处的连系梁内力减小较多，其他梁或柱的内力变化很小。与原结构类似，在补偿结构中，钢框架柱之间的竖向变形差异远远小于柱－筒之间的竖向变形差异。
关键词：钢框架－钢筋混凝土核心筒体系；楼层组优化补偿方案；竖向变形差异；结构内力

Influence of the vertical deformation compensation of corewall systems on the characteristics of steel frame-reinforced concrete structures

Zhou Xuhong¹　 Huang Xiangxiang²　 Wang Yihong¹　 Di Jin¹　 Liu Yongjian¹
（1. Chang’an University，Xi’an 710064，China；2. Hunan University，Changsha 410082，China）

Abstract：After comparing different structural compensation schemes，an optimal scheme is presented for compensating the differential deformations between columns and corewall of steel frame-reinforced concrete corewall structures，and its effects on the internal force and the deformation of the structure are also discussed. The SAP2000 software is employed to calculate the differential deformations，including the effects of concrete creep and shrinkage. Gravity loads are applied to the whole structure，floor by floor，based on the superposition principle. The study points out that an optimal compensation scheme can indeed not only ensure the compensation precision，but also facilitate the construction process. When optimal compensation scheme is adopted，the maximum accumulating differential deformations between columns and corewall can be reduced sharply，thus ensuring the beams and plates to remain horizontal. In the compensated structure，the changes of internal forces of all steel beams and columns are relatively small，except the coupling and secondary beams at the corners. Similar to the original structure，the differential deformations between columns are far smaller than those between columns and corewall in the compensated structure.
Keywords：steel frame-reinforced concrete corewall structure；optimal compensation scheme；differential deformation between columns and corewall；internal force of structure
Ｅ-mail：zhouxuhong@126.com

新老混凝土粘结面的抗冻融劈拉性能试验研究

李平先^1，2　 赵国藩²　 张雷顺¹
（1. 郑州大学，河南郑州 450002；2. 大连理工大学，辽宁大连 116023）

摘要：采用新老混凝土粘结复合立方体试件，通过快速冻融试验，对先冻融后粘结和先粘结后冻融两种情况的新老混凝土粘结试件在水饱和状态下的冻融劈裂性能进行了试验研究，探讨了冻融循环次数、粘结面粗糙度和界面剂类型对粘结面劈裂抗拉强度的影响。界面的粗糙度为0.23~6.9 mm，界面剂选用水泥净浆、水泥砂浆和掺加10%UEA膨胀剂的水泥净浆。试验结果表明，无论是先冻融后粘结还是先粘结后冻融的新老混凝土粘结试件，其粘结面的劈裂抗拉强度均随冻融循环次数的增加而降低，表现为冻融初始阶段的缓降和冻融循环一定次数后的陡降，特别是先粘结后冻融试件，其下降程度更加显著。根据试验，适当的粗糙度和水泥砂浆界面剂对粘结质量有较好的改善作用。在试验的基础上，对粘结面的冻融损伤机理进行了初步分析。
关键词：新老混凝土；冻融循环；劈裂强度；粗糙度；界面剂

An experimental study on the bond splitting behavior of the interface between new-old cocretes under freeze-and-thaw cycles

Li Pingxian^1，2　 Zhao Guofan²　 Zhang Leishun¹
(1. Zhengzhou University，Zhengzhou 450002，China；2. Dalian University of Technology，Dalian 116023，China)

Abstract：Using composite cubic specimens of new-old concrete, the bond splitting behaviors of the interface of water-saturated new-old concrete under freeze-and-thaw cycles is studied, for two different situations: bonding after freeze-and-thaw，and bonding prior to freeze-and-thaw. The effects of freeze-and-thaw, roughness (0.23~6.9 mm) and adhesion agent (including cement paste, cement mortar and cement paste with 10 per cent UEA expanding agent) are investigated. The test results indicate that the bond splitting tensile strength decreases significantly with increasing number of freeze-and-thaw cycles，that the rate of decrease is greater for those specimens bonded prior to freeze-and thaw, and that appropriate roughness and cement mortar may improve the bonding strength. Based on the test results，a preliminary analysis is conducted on the mechanisms of bonding.
Keywords：new-old concrete；freeze-thaw cycling；splitting tensile strength；roughness；adhesion agent
E-mail：lipingxian@zzu.edu.cn

大截面混凝土箱梁结构的计算方法及其应用

陈衡治¹　 谢　 旭¹　 陈海滨¹　 黄剑源²
( 1. 浙江大学，浙江杭州310027；2. 宁波大学，浙江宁波315211)

摘要：为了用少量单元获得高精度的混凝土箱梁空间应力计算结果，提出考虑截面形状组成并在梁轴方向应用高阶位移插值函数的中厚板梁段结构分析方法。以杭州湾跨海大桥非通航孔桥梁的设计方案为例，与三维实体有限元计算结果的比较表明，该方法在梁纵向只需划分少量单元就可以得到高精度的结果，适用于壁厚变化的大截面混凝土箱梁桥结构的计算分析。
关键词：大截面；箱梁桥；板梁段；结构分析

An analytical method and its application for large-section PC box girder bridges

Chen Hengzhi¹　 Xie Xu¹　 Chen Haibin¹　 Huang Jianyuan²
(1.Zhejiang University，Hangzhou 310027，China；2.Ningbo University, Ningbo 315211, China )

Abstract: In order to obtain accurate spatial stresses of box girder with a small number of elements，an analytical method for large-section PC box girders is proposed. A higher order displacement function in the axial direction is introduced，and the section composition is considered. Taking the Hangzhou Bay Bridge as an example，both 3-D solid FEM and the proposed method are compared. The results indicate that high accuracy can be achieved with a small number of elements by using the proposed method.
Keyword: large-section；box girder bridge；block element；structural analysis
E-mail: chenhengzhi78@yahoo.com.cn

结构参数小幅变化后桥梁固有模态修正的矩阵摄动法

刘寒冰　　秦绪喜　　王书娟　　谭国金

（吉林大学，吉林长春130025）
摘要：桥梁设计阶段构件参数的改变、施工阶段体系的转换和施工误差、使用过程中的磨损、损伤都会直接造成桥梁质量阵、刚度阵的改变，其动力特性也随之改变。遇到结构参数频繁小幅变化的情形，用经典的方法获得其动力特性就需要多次求解广义特征问题，这对于大型复杂结构来说是非常麻烦和费时的。提出应用矩阵摄动法来求解桥梁结构改变后的固有模态。用ANSYS对某悬索桥进行自由振动分析，然后以从分析结果中提取出的频率、刚度阵、质量阵及振型数据为基础，采用矩阵摄动法对结构参数小幅度调整后的固有模态进行相应的计算，并将所得结果与结构修改后的有限元计算结果进行比较。结果表明本文所提出的应用矩阵摄动法修正固有模态的方法是有效的、可靠并且省时的，便于工程应用。
关键词： 悬索桥；固有模态； 参数修改； 矩阵摄动法

Matrix perturbation method for natural model analysis
of bridges with small parametric variations

Liu Hanbing　 Qin Xuxi　 Wang Shujuan　 Tan Guojin
(Jilin University，Changchun 130025，China)

Abstract: Modification of element parameters at design stage，system transformation and construction error，any structural abrasion and damage during the service stage will directly alter the mass and stiffness matrices of a bridge. Correspondingly，bridge’s dynamic properties may also change. When structural parameters vary frequently in small magnitudes，one may have to solve for the generalized eigen-value problems several times in order to acquire the dynamic properties of a bridge. Obviously，this undertaking is very tedious and time consuming，especially when the bridge structure is large and complex. Presented in the paper is a matrix perturbation method for calculating the natural vibration modes of a bridge structure with parametric modifications. To demonstrate the proposed method，the free vibration analysis of a suspension bridge is carried out using ANSYS. Then，using the frequencies，stiffness matrix，mass matrix and vibration shapes abstracted from the analysis，the matrix perturbation method is adopted to compute natural modes of the structure with small parametric adjustments. The results are compared with those from the finite element method，and it indicates that the proposed method is quite effective，reliable，efficient and convenient for design applications.
Keywords：suspension bridge；natural modal；parameter modification；matrix perturbation method
E-mail：lhb@jlu.edu.cn

循环载荷下纤维薄板增强RC梁的疲劳性能研究

姚国文^1，2 黄培彦¹
（1. 华南理工大学，广东广州 510640；2. 重庆交通大学，重庆 400074）

摘要： 通过建立循环载荷下碳纤维薄板(CFL)增强RC梁的累积损伤模型，并与增强梁的疲劳试验结果进行对比，研究增强构件的疲劳性能和损伤、破坏过程。试验发现CFL增强RC梁的疲劳损伤演化历程包括混凝土开裂、CFL与混凝土剥离、钢筋屈服等过程，具有明显的疲劳损伤成核、稳定扩展、失稳扩展三阶段发展规律，根据增强梁的载荷、挠度历程可以得到抗弯刚度演化历程。研究结果表明用CFL增强RC梁的剩余抗弯刚度来度量其疲劳损伤变量具有明确的物理意义，在此基础上建立的疲劳损伤演化方程能够准确模拟CFL增强RC梁的疲劳损伤破坏过程，进一步结合抗弯刚度可预测其剩余疲劳寿命。
关键词： 疲劳累积损伤模型；循环载荷；碳纤维薄板；钢筋混凝土梁；抗弯刚度

A Study on the fatigue behavior of RC beams strengthened with fiber laminates

Yao Guowen^1，2 Huang Peiyan¹
(1. South China University of Technology，Guangzhou 510640，China；
2. Chongqing Jiaotong University，Chongqing 400074，China)

Abstract：The fatigue behavior and failure modes of RC beams strengthened with carbon fiber laminates (CFL) under cyclic loading are studied by using an accumulative fatigue damage model based on fatigue experiments. The fatigue damage of the strengthened beams includes concrete cracking，CFL de-bonding from concrete and steel bar yielding. Three stages of fatigue damage，i.e.，nucleating，steadily expanding and transiently expanding，are obvious. The damage is defined by using the residual bending rigidity of the strengthened beam with obvious physical meaning. The results indicate that the accumulative fatigue damage model describing the damage and failure process of CFL strengthened RC beams is in good agreement with fatigue experiments，and can predict the residual fatigue lives according to the bending rigidity.
Keywords：accumulative fatigue damage model；cycle loading；carbon fiber laminate；RC beam； bending rigidity
Ｅ-mail：yaoguowen@sina.com

斜拉桥结构健康监测系统的设计与实现（I）:系统设计

李　惠　 欧进萍
（哈尔滨工业大学，黑龙江哈尔滨 150090）

摘要: 结构智能健康监测愈来愈成为重大工程结构健康与安全的重要保障技术，也愈来愈成为重大工程结构损伤积累乃至灾害演变规律的重要研究手段。斜拉桥健康监测系统是由传感器子系统、数据采集与传输子系统、结构分析子系统和数据管理子系统组成的，不同系统的谐调运行需要通过系统集成技术来实现。首先从监测内容、等级和功能等方面研究健康监测系统的总体设计原则；然后，分局部监测变量和整体监测变量研究传感器的最优测点确定方法和原则，提出传感器的选型原则；提出数据采集系统的总线设计方法和方案，研究数据采集系统硬件和软件设计方法；提出数据传输系统的设计原则和方法；给出斜拉桥基于构件和基于结构体系的安全评定设计方法；提出斜拉桥施工监控、成桥试验、运营健康监测和养护管理四位一体系统的共享设计原则；提出系统集成技术的软件设计方法。
关键词：桥梁；健康监测系统；设计方法；系统集成；智能

Design and implementation of health monitoring systems for
cable-stayed bridges(I): design methods

Li Hui　 Ou Jinping
(Harbin Institute of Technology，Harbin 150090，China)

Abstract: The structural health monitoring(SHM)system is becoming a technique for ensuring the health and safety of civil infrastructures and also an important means for studying the damage accumulation or even disaster evolution characteristics of civil infrastructures. An SHM system consisted of a sensor module，a data acquisition module，a data transmission module，a structural analysis module，and a data base module. An integrated technique is employed to make all modules run automatically. General design principles of the SHM systems for cable-stayed bridges，including the monitored variables，grade and function，are studied. The design method for optimal sensor locations and performance is analyzed. The design methods for the data acquisition module，including the bus master scheme，hardware and software，are proposed. The design methods for the data transmission module and safety evaluation at both member and structure levels are also presented. The design of a SHM system for cable-stayed bridges should be considered together with the design of the construction monitoring system static and dynamic loading test and management systems. The design method for a system integration approach is also proposed.
Keywords: bridge；health monitoring system；design approach；system integration；intelligent
E-mail: lihui@hit.edu.cn

斜拉桥结构健康监测系统的设计与实现（II）：系统实现

李　惠　 欧进萍
（哈尔滨工业大学，黑龙江哈尔滨 150090）

摘要: 采用“斜拉桥结构健康监测系统的设计与实现(I)－系统设计”中所建立的设计方法，分别为两座大型斜拉桥设计并实现长期实时健康监测系统和定期实时健康监测系统：滨州黄河公路大桥长期实时健康监测系统和哈尔滨松花江大桥定期实时健康监测系统。研究两座大型斜拉桥结构健康监测系统的总体设计方案、子系统的设计方案和硬软件设备及其实现、系统的集成技术及其实现方法；分析两套健康监测系统在成桥试验和运营中监测的桥梁结构荷载和静动力反应。结果表明，两座斜拉桥结构健康监测系统均能协调运行，实现了预期设计功能；系统中布设的光纤光栅应变和温度传感器测试精度高、耐久性好、抗电磁干扰性能强；系统中建立的远程无线微波通讯系统可以实时传输和再现监测信号。
关键词：斜拉桥；健康监测系统；光纤光栅传感器；无线传输技术；系统集成

Design and implementation of health monitoring systems for
cable-stayed bridges(II): implementations

Li Hui　 Ou Jinping
(Harbin Institute of Technology，Harbin 150090，China)

Abstract: Two structural health monitoring(SHM)systems for the Shandong Binzhou Yellow River Highway Bridge and Harbin Songhua River Bridge，respectively were designed and implemented by employing the design method proposed by the authors，presented in the proceeding article of two-paper in sequel. The system for the first case ran in real-time and the data were saved and downloaded at a website at any instant. While for the later case the system ran at regular intervals and only the database was permitted to be visited at the website. The frameworks of the health monitoring systems were first determined. Then，the type，location and performance of the sensors，the data acquisition module，wireless communication system，database，and system integration techniques were studied，determined and implemented. These systems have been running and collecting data since the bridges were open to traffic. The results indicated that the performance of the two systems has achieved the desired objectives. In addition，the performance of the optical fiber Bragg-grating sensors measuring the applied strain and temperature for long-term monitoring purpose even under -50℃ and 50℃ ambient temperatures was verified. The capacity of the microwave wireless communication system transmitting and retrieving data in real-time for the health monitoring system was also investigated.
Keywords: cable-stayed bridge；health monitoring system；optical fiber Bragg-grating sensor；wireless commun-ication technology；system integration
E-mail：lihui@hit.edu.cn

轴向荷载作用下梁结构动力特性的随机分析

程　进　 肖汝诚
（同济大学，上海 200092）

摘要：传统梁结构动力特性分析方法由于忽略结构参数的不确定性而不能满足实际工程设计需要，因此，将响应面法(RSM)、有限元法(FEM)和蒙特卡罗法各自的优点相结合，提出一种新的结构随机动力特性计算方法－混合分析法。该方法的最大特点是有效地利用响应面法(RSM)、有限元法(FEM)和蒙特卡罗法(MCS)各自的优点，并将其充分地结合起来。然后，运用该方法分析一简支梁自振频率的统计值。结果表明基于确定性模型的梁结构频率响应分析仅能给出频率响应的均值，忽略结构随机参数对频率响应的影响。为获得准确的频率响应值，有必要在今后的结构动力特性分析中考虑结构参数随机性的影响。最后，进行梁结构随机动力特性计算的敏感性因素分析，并指明影响梁结构动力特性的主要随机因素。
关键词：梁结构；动力特性；随机分析；响应面

Stochastic analysis of the dynamic characteristics of beams subjected to axial loads

Cheng Jin　 Xiao Rucheng
(Tongji University，Shanghai 200092，China)

Abstract: Due to ignoring the effect of the randomness of structural parameters，conventional deterministic analysis cannot provide complete information regarding the dynamic characteristics of beams. A stochastic finite-element-based algorithm for probabilistic free vibration analysis of beams is proposed through combining the advantages of the response surface method，the finite element method and Monte Carlo simulations. Using the proposed method，a probabilistic free vibration analysis of a simply supported beam is performed. The results show that the free vibration analysis based on deterministic models gives only the mean natural frequency and misses the deviations present because of randomness in the structural parameters. For accurate natural frequency，it is necessary that the analysis technique incorporate the effect of structural parameter randomness. In addition，the effects of various parameters on the statistical moments of the frequency response of beams are investigated.
Keywords: beam；dynamic characteristics；stochastic analysis；response surface
E-mail: chengjin@tsinghua.org.cn

非饱和膨胀土总强度指标随饱和度变化规律

杨和平　 张　锐　 郑健龙
( 长沙理工大学，湖南长沙 410076 )

摘要：建立在有效应力基础上的非饱和土强度理论公式参数测试复杂、不便于工程应用，而包含吸附强度的总强度指标也能反映非饱和土的强度特性且易于获取。为此，以土水特征曲线为理论依据，采用抽气饱和、风干脱水法控制试样的饱和状态，用常规直剪仪对不同状态下的宁明膨胀土进行固结快剪试验，得到其总强度指标随含水量、饱和度的增大而衰减的变化规律。其中，黏聚力、内摩擦角的对数和含水量之间以及内摩擦角与饱和度之间成线性关系；黏聚力随饱和度的变化可用二次抛物线描述。对该规律的普遍性还用廖世文、卢肇钧同类试验结果的分析来加以检验。此外，针对膨胀土路堑边坡滑坍的特点，对如何将非饱和膨胀土总强度指标用于边坡稳定性分析进行探讨，研究结果可为工程应用提供参考。
关键词：非饱和；膨胀土；直剪试验；抗剪强度；含水量；饱和度

Variation of the total shear strength of unsaturated expansive
soils with degree of saturation

Yang Heping　 Zhang Rui　 Zheng Jianlong
(Changsha University of Science and Technology，Changsha 410076，China)

Abstract: The shear strength formula for unsaturated soils，based on the effective stress principle，is difficult to apply in engineering practice，because of the complications in measurements of its parameters. However, the indices of total shear strength including suction strength not only can express the features of the strength of unsaturated soils，but also can be easily obtained. For this reason，several groups of Ningming expansive soil specimens were kept under a certain range of saturations by using vapor extraction and air-drying methods，according to the theory of soil-water characteristic curve. Then，a series of tests on the specimens were conducted with consolidation and quick shearing method using a conventional direct shear apparatus. The total shear strength decreases with increase of saturation degree. Furthermore，the relationships between the logarithm of cohesive force，frictional angle and saturation degree are linear；the variation of cohesive force with saturation degree can be described by a parabolic relationship. This relationship was also validated by the test results obtained by Liao Shiwen and Lu Zhaojun. Application of the indices of total shear strength to slope stability analysis was also discussed.
Keywords: unsaturated expansive soil；direct shear test；the shear strength；water content；saturation degree
E-mail：cscuyang@163.com

适用于软岩边坡加固的压力分散型预应力锚索锚固机理研究

金永军¹　 何满潮²　 王树仁³　 刘成禹²
（1.北京国电华北电力工程有限公司，北京 100011; 2.中国矿业大学，北京 100083; 3.北京科技大学, 北京 100083）

摘要：利用有限差分程序FLAC对压力分散型预应力锚索的锚固机理进行了研究。和拉力集中型锚索相比，压力分散型锚索有以下优点：锚固段浆体轴力峰值仅为拉力集中型的1/n（n为承载体的数量）且为受压状态；剪力峰值较小且能较均匀地分布于整个锚固长度上；可以提供较大的锚固力。这些特点说明压力分散型锚索更适用于软岩边坡的加固，增加承载体的数量是提高压力分散型锚索锚固力、改善其受力状态的有效途径。
关键词：软岩；边坡；压力分散型预应力锚索；锚固机理；数值模拟

Study on the anchoring mechanism of pre-stressed anchor cable with
dispersive pressure suitable for soft-rock slope reinforcing

Jin Yongjun¹　 He Manchao²　 Wang Shuren³　 Liu Chengyu²
(1. Beijing North China Power Engineering Ltd. Co.，Beijing 100011，China；
2. China University of Mining and Technology，Beijing 100083，China；
3. Beijing University of Science and Technology，Beijing 100083，China)

Abstract: This paper researched the anchoring mechanism of one new type of pre-stressed anchor cable, which is pre-stressed anchor cable with dispersive pressure (PACDP), using FLAC. Results indicate that PACDP has several advantages and is more suitable for soft rock slope reinforcing compared with pre-stressed anchor cable with concentrated tension (PACCT). The peak value of axial stress of PACDP is only 1/n (n is the number of supporting) of that of PACCT, and the grouted part is in compression. In addition, the peak value of shear stress between the grouted part and the drilling wall of PACDP is also smaller than that of PACCT, and it is evenly distributed along the axis of the anchor. PACDP can provide larger anchoring force than PACCT. It is an effective way to enhance the anchoring force and to improve the mechanical conditions through increasing the number of supporting.
Keywords: soft rock；slope；pre-stressed anchor cable with dispersive pressure；anchoring mechanism；numerical simulation
E-mail: jyjun4693@163.com

深基坑支护结构—土非线性共同作用弹性地基反力法

邓子胜
(五邑大学，广东江门 529020)

摘要：为使深基坑支护设计考虑支护结构－土的非线性共同作用，将地基土的水平基床系数视为深度和围护墙位移的非线性函数，建立作用于围护墙上的土压力增量的计算模型。进而根据一般弹性地基梁的挠曲微分方程，推导出考虑非线性共同作用的弹性地基梁的挠曲微分方程，并在分析深基坑开挖与回筑全过程中各工况支护结构的受力与变形特征的基础上，给出非线性共同作用弹性地基反力法的计算模型与求解方法。工程算例表明，该方法比现行规程设计方法得到的围护墙计算位移更接近实测位移，且计算参数的确定更为方便，具有较强的实用性。
关键词：深基坑；非性线共同作用；弹性地基反力法；水平基床系数

An elastic subgrade reaction method considering nonlinear interaction between protection-structure and soil for deep excavations

Deng　 Zisheng
(Wuyi University，Jiangmen 529020，China)

Abstract：To consider the nonlinear interaction between soil and the protection-structure for deep excavation designs，the horizontal foundation coefficient of soil is taken as a nonlinear function of the depth and the wall deflection. In this connection a mathematical model is established for calculating the earth pressure increment on the wall. The differential equation of the elastic subgrade beam to consider the nonlinear interaction is derived based on the equation of the general elastic subgrade beam. A computer model is presented to calculate the loading and deformation features of the protection-structure during different construction stages. The calculation results indicate that the wall displacements calculated by this method are closer to the actual displacements than those by using the method suggested in the design code，and the calculation parameters can be obtained in a more convenient manner.
Keywords：deep excavation；nonlinear interaction；elastic subgrade reaction method；horizontal foundation coefficient
E-mail：dzisheng@163.com

坝基混凝土防渗墙应力位移影响因素分析

王 刚　　张建民　　濮家骝
（清华大学，北京　 100084）

摘要：以溪洛渡围堰的设计对比方案为例，采用二维和三维有限元方法计算堰体和防渗墙的应力位移，揭示防渗墙应力位移随主要影响因素的变化规律。研究表明：防渗墙的水平位移主要由堰体型式决定；防渗墙材料的模量越高，其适应堰体变形的能力越差，安全性就越低；降低防渗墙上部材料的模量能在一定程度上降低防渗墙的应力；墙厚在合理范围（0.8~1.2 m）内变化，对防渗墙的应力位移影响很小；三维效应对防渗墙的中间断面应力位移影响较小，但两岸陡坡处可能变危险。上述结论可为同类土石坝和围堰的方案设计和优化提供参考。
关键词：防渗墙；应力变形；围堰；土石坝；溪洛渡

An evaluation of the factors influencing the stress and
deformation of concrete diaphragm wall in dams

Wang Gang Zhang Jianmin Pu Jialiu
（Tsinghua University，Beijing 100084, China）

Abstract: Stress and deformation analyses were performed on the design schemes of Xiluodu upstream cofferdam by using 2-D and 3-D FEM. Based on the calculation results，main factors influencing the stress and deformation of the diaphragm wall under a dam were revealed. The major findings include the followings: (1) the horizontal displacement of the diaphragm wall is governed by the dam type； (2) the higher the wall’s modulus，the more dangerous the wall becomes； (3) the stress in the wall can be significantly reduced by decreasing the modulus of the filled materials above the wall； (4) a change of wall thickness within a reasonable range(from 0.8 m to 1.2 m)has little effect on the stress and displacement of the wall； (5) 3-D effect of the valley is of little significance for the stress and deformation of the middle wall section, whereas sections near steep slopes may become more dangerous.
Keywords: diaphragm wall；stress-deformation；cofferdam；embankment；Xiluodu hydropower station
Ｅ-mail：wg00@mail.tsinghua.edu.cn

高能级强夯作用下孔压测试与分析

水伟厚¹　 王铁宏²　 王亚凌³
（1. 上海现代建筑设计集团申元岩土工程有限公司，上海 200011；2. 中华人民共和国建设部，北京 100835；3. 中化岩土工程有限公司，北京 102600）

摘要：结合在沿海某回填地基上实施的国内首次10000 kN·m高能级强夯系列试验，对试验过程中不同深度与距离的孔隙水压力（以下简称孔压）进行较为全面的测试与分析，得到夯击过程中孔压增长与消散特征。结果表明：犬牙式孔压增量曲线显示的孔压消散速率较台阶式曲线为快，10000 kN·m强夯的有效加固深度超过11.8 m，主夯点间距宜为12～13.5 m，夯击击数宜为14～16击。提出一些可供高能级强夯地基处理工程设计、施工和监测参考的建议。
关键词：高能级强夯；10000 kN·m；孔隙水压力

An experimental study on pore water pressure during a 10000 kN·m high energy level dynamic compaction

Shui Weihou¹　 Wang Tiehong²　 Wang Yaling³
(1. Shanghai Shenyuan Geotechnical Engineering Co. Ltd.，Shanghai 200011，China；
2. Ministry of Construction P.R.China，Beijing 100835，China；
3. China Zhonghua Geotechnical Engineering Co.Ltd.，Beijing 102600，China)

Abstract: A series of energy levels of Dynamic Compaction(DC)experiments are successfully conducted at a rubble fill site in a coastal area，for the first time in China. The test results of pore water pressure are presented and analyzed. The development and dissipation of pore water pressure are obtained during a 10000 kN·m DC. The results indicate: the pore water dissipates faster than the one shown by the step curve；the effective depth of improvement exceeds 11.8 m during the 10000　kN·m DC；the main compaction-point intervals of the 10000 kN·m DC are 12～13.5 m，whereas 14～16 m are suitable for high energy level compactions.
Keywords: high energy level dynamic compaction；10000 kN·m；pore water pressure
E-mail：sh191@126.com

克里格法在岩土工程勘察和地基处理与基础设计中的应用

刘俊杰¹　 乔德清²
（1. 大连大学院士创业园，辽宁大连 116622；
2. 辽宁东地建筑岩土工程有限公司，辽宁沈阳110016）

摘要: 根据勘探钻孔获得的岩土层工程地质性质及分布赋存状况绘制的工程地质剖面图，具有相当大的人为随意性，由此会导致地基处理和基础设计的某种盲目性。建筑场地勘探点布置一般成比较标准的正交网格状分布，这正是克里格法对样品点分布与插值估计点分布的基本要求。克里格法可以给出直观的图形定性结果，例如某目的岩土层的三维块体图；同时，也能够给出理论分析定量结果，即相应目的层的试验变异函数曲线及其理论拟合曲线、理论变异函数模型及其各相关参数。因此，可使单纯依据勘探钻孔获得的定性成果进化为科学的定量成果，保证科学优化设计、精确预算、合理施工。目前还只能将克里格法作为岩土工程勘察成果分析的一种辅助手段，采用该方法可减少或避免随意性与盲目性，检验岩土工程勘察成果，从地基处理和基础设计角度看，为确保建筑物的安全和纠正工程造价预算偏差，该方法可为岩土工程勘察规范制定提供参考依据。
关键词: 岩土工程勘察；地基处理与基础设计；克里格法；辅助手段

Application of Kriging method for geotechnical engineering exploration and subgrade treatment and foundation design

Liu Junjie¹　 Qiao Deqing²
（1. Institute of Civil Engineering and Architecture of Dalian University，Dalian 116622，China；2. East-ground Construction and Geotechnical Engineering Limited Company of Liaoning，Shenyang 110016，China）

Abstract: Artificial uncertainties in plotting geological cross-sections based on engineering geological properties and data from exploratory holes may lead to ambiguities in subgrade treatment and foundation design. Application of Kriging mechod，an unbiased and least error optimum reserve estimation method，could reduce or avoid such ambiguity. Using this method，both the intuitional qualitative results，such as the 3-D block diagram of the target layer，and the theoretical quantitative results，such as the experimental variogram of the layer，the theoretical fitting curve，and the theoretical variogram model and related parameters，can be obtained. Therefore，application of the Kriging method in geotechnical engineering exploration, subgrade treatment and foundation design can assist one to realize optimum design, accurate estimation and rational construction organization. So far，Kriging method is employed just an aid to analyzing and verifying the data of geotechnical engineering exploration to avoid randomness and ambiguity. Thus，it is necessary to incorporate the Kriging method into the code for geotechnical engineering investigation，also to insure the safety of buildings and rational budget of subgrade treatment and foundation design.
Keywords: geotechnical engineering exploration；subgrade treatment；foundation design；Kriging method
E-mail：l_56@163.com

长期荷载作用下土工格栅蠕变特性的试验研究

栾茂田¹　 肖成志¹　 杨　 庆¹　 裴建军²　 李业学³
(1. 大连理工大学，辽宁大连 116024；2. 青岛颐中格栅股份有限公司，山东青岛 266111；3.中国矿业大学，北京 100083 )

摘要：为探讨长期荷载作用下土工格栅的蠕变特性，在不同的外加荷载和环境温度的各种组合条件下，进行土工格栅的室内蠕变试验, 以此获得格栅的蠕变关系曲线、载荷－应变等时曲线及拉伸模量的变化特征，并进行综合对比分析。根据试验与分析发现：荷载水平、环境温度和材料生产工艺是影响土工格栅长期蠕变特性的重要因素。进而，采用时温叠加原理, 对于某一给定环境温度下确定土工格栅长期强度的经验估算模式和蠕变强度折减系数。试验结果与理论分析为土工格栅加筋结构长期工作性能的分析与评价提供参考依据。
关键词：土工格栅；加筋结构；蠕变试验；时温叠加法；蠕变折减系数

An experimental study on the creep behavior of geogrids
under long-term external loading

Luan Maotian¹　 Xiao Chengzhi¹　 Yang Qing¹　 Pei Jianjun²　 Li Yexue³
(1. Dalian University of Technology，Dalian 116024，China；
2. Qingdao Etsong Geogrids Co.，Ltd.，Qingdao 266111，China；
3. China University of Mining and Technology，Beijing 100083，China)

Abstract：The creep behaviour of geogrids is fundamental to evaluating the long-term performance of geogrid-reinforced earth structures under long-term external loading. A series of creep tests of geogrids are conducted in the laboratory under different combinations of external loads and surrounding temperatures. The characteristics of the creep curve，the isochronous load-strain relationship and the tensile modulus of geogrid are obtained. A comprehensive comparative study of the test data is also made. Based on the experimental results and theoretical analyses，it is shown that the creep behavior of geogrids is significantly influenced by load level，surrounding temperature and fabrication workmanship. Furthermore，a method based on the principle of time-temperature superposition is applied to establish empirical formulae for estimating the long-term strength and the reduction factor of creep strength of geogrids. The proposed model can be very useful for analysis and evaluation of the long-term performance of geogrid-reinforced earth structures when the creep behavior of geogrids is taken into account.
Keywords：geogrid；reinforced earth structure；creep test；time-temperature superposition；reduction factor of creep strength
E-mail：mtluan@dlut.edu.cn

复合矿渣微粉对混凝土抗氯离子侵蚀性能影响的野外试验研究

杨医博　 梁　 松　 莫海鸿　 陈尤雯
（华南理工大学，广东广州 510640）

摘要：采用测定混凝土中氯离子显色渗透深度的方法，研究大掺量矿渣微粉混凝土和大掺量复合矿渣微粉混凝土的抗氯离子侵蚀性能，并与纯水泥混凝土进行对比。发现经3年海水浸泡后，在0.36水胶比的混凝土中，用比表面积为400 m2/kg的矿渣微粉取代65％的水泥可降低混凝土氯离子显色渗透深度75％，增加矿渣微粉细度至600 m2/kg或使用复合矿渣微粉均可进一步降低混凝土氯离子显色渗透深度50％左右。结果表明采用大掺量复合矿渣微粉是一种提高混凝土抗氯离子侵蚀能力的有效手段。
关键词：矿渣微粉；复合矿渣微粉；混凝土；海水；氯离子

Chloride penetration resistance of concrete with multiplex-slag after 3 years of exposure in seawater environment

Yang Yibo Liang Song Mo Haihong Chen Youwen
（South China University of Technology，Guangzhou 510640，China）

Abstract：The chloride penetration resistance of concrete was investigated by measuring the colorimetric chloride penetration depth. The specimens were exposed in seawater environment for 3 years. The concrete types include plain Portland cement concrete，high volume slag concrete with different slag fineness，and high volume multiplex-slag concrete. The water-binder-ratio was 0.36. Test results confirm that concretes containing high volumes of slag or multiplex-slag exhibit improved chloride penetration resistance when compared with plain Portland cement concrete. Using slag with a fineness of 400 m2/kg to replace 65% of cement could decrease the colorimetric chloride penetration depth by as much as 75%，and increasing the fineness of slag to 600 m2/kg or using multiplex-slag could further decrease the colorimetric chloride penetration depth by about 50%. The results indicate that using high volume of multiplex-slag could be an effective method for improving the chloride penetration resistance of concrete.
Keywords：slag；multiplex-slag；concrete；seawater；chloride ion
E-mail: yangyibo@21cn.com

火灾时隧道内烟流流动状态试验研究

闫治国¹　 杨其新²　 朱合华¹
（1. 同济大学，上海 200092；2. 西南交通大学，四川成都 610031）

摘要：通过大比例火灾模型试验，研究火灾时隧道内烟流流动状态、烟流速度变化以及通风对烟流流动状态的影响。试验模型隧道长100 m，内径1.8 m。火源采用燃烧床盛放油料模拟，试验中设定了A、B、C三个火灾规模用以模拟实际隧道火灾场景。试验结果表明，点火后，隧道内火区、火区下游烟流速度在2～8 min内增加很快，明显大于点火前风速，且其增幅随通风风速、火灾规模的不同而变化。同时，随着火势的逐渐减弱隧道内烟流速度也逐渐减小，并趋于初始风速。试验结果建议对于一般的限制或禁止油罐车通行的隧道，火灾时，隧道内应尽快建立起2～3 m/s的纵向风流以抑止烟气的逆流。
关键词：隧道；火灾；火灾试验；烟流流动；临界风速

An experimental study of smoke flow in tunnel fire
Yan Zhiguo¹　 Yang Qixin²　 Zhu Hehua¹

（1. Tongji University，Shanghai 200092，China；2. Southwest Jiaotong University，Chengdu 610031，China）

Abstract: To investigate the behaviors of smoke when fire occurs in a tunnel，a series of fire tests were conducted in a large-scaled model tunnel. The scopes of the tests include smoke flowage，variation of smoke velocity with time and effect of forced ventilation on smoke flowage. The model tunnel is 100 m long，and it has a circular cross-section with an inner diameter of 1.8 m. An oil pool is employed as a fire source. Three levels of fire loads，categorized as A，B and C，are employed to simulate different fire scenarios. The results show that the smoke velocity at the fire point and in the area behind the fire point increases significantly from 2 min to 8 min after ignition. The increment of velocity varies with forced ventilation and fire load. The smoke velocity gradually decreases to the original value in the tunnel while fire attenuates. The results suggest that a longitudinal forced ventilation of 2~3 m/s should be established as soon as possible to prevent back-flow of hot smoke in case fire breaks out in a tunnel that prohibits tank trucks.
Keywords: tunnel；fire；fire testing；smoke；critical velocity
E-mail: yanzguo@126.com

全站仪自由设站隧道围岩变形非接触监测理论和方法的研究

杨松林　 刘维宁　 师红云　 黄　 方
（北京交通大学，北京100044）

摘要：钢尺收敛计隧道围岩变形量测由人工拉尺读数，效率低，与施工相互干扰，测量结果容易受人为因素影响。为满足现代隧道快速、大跨、安全施工需求，提出全站仪围岩变形非接触量测单站、双站自由设站三维坐标法和单站、双站独立坐标测线法的概念和方法，推导围岩变形监测全站仪自由设站坐标转换数学模型。阐述自动全站仪隧道围岩变形非接触监测系统的组成、开发及其特点。以北京东直门地铁隧道施工围岩变形监测为例，说明系统的数据处理、精度评定、图形分析和预报功能，该系统以其高精度、自动化、简便实用的优点在隧道围岩变形监测中起到重要作用。
关键词：全站仪；自由设站；非接触监测；围岩变形；数据处理；分析预报

A study on the theory and method of non-contact monitoring for tunnel rock deformation based on free stationing of a total station

Yang Songlin Liu Weining Shi Hongyun Huang Fang
(Beijing Jiaotong University，Beijing 100044，China)

Abstract: Monitoring the convergence of the surrounding rocks of a tunnel, by drawing rulers and manual reading, is rather inefficient. It interferes with construction，and the measured results can be easily influenced by human factors. To satisfy the requirements of improved advancement rate，large span and safe construction for modern tunnel engineering，the conception and technique of several non-contact monitoring methods, such as single station，double-station 3-D and measured line schemes，are presented，and a coordinate conversion model of the free stationing system is derived. Based on an automated total station，the monitoring and analysis system for tunnel rock convergence is described，including its composition，development and features. The data processing, accuracy analysis and forecasting of the system are demonstrated by using a practical application to the Dongzhimen subway construction project in Beijing. The results show that this system plays an important role in monitoring tunnel rock convergence with high degrees of accuracy，automation，practicability and efficiency.
Keywords: total station；free stationing；non-contact monitoring；enclosing rock deformation；data processing；analysis and forecast
E-mail：slyang@center.njtu.edu.cn

导洞—隔离桩体系工作机理研究与侧向变形分析

姚海波¹　　　王梦恕¹　　　张顶立¹　　　陈　浩²
（1. 北京交通大学，北京 100044；2. 中国铁路隧道集团第二工程处，北京 100078）

摘要：为了精确了解导洞－隔离桩结构体系在屏蔽隧道施工所造成的环境效应过程中的受力和变形规律，基于隧道开挖所致土体变形特点的研究，分析施工过程中导洞—隔离桩结构体系的受力特点。在此基础上，由导洞内侧（近隧道侧）土体位移与土体极限状态（朗肯被动土压力状态）时土体位移的比值，修正土体侧压力系数，使计算结果更趋近于真实状态。同时，采用梁和弹性地基梁模型模拟隔离桩的受力和变形特点，将导洞的支撑作用等效为一水平支座弹簧，通过导洞受力分析，计算弹簧刚度。利用两个分解的模型，分别模拟隧道台阶法施工中上、下导坑的开挖，再组合为整体效应。计算结果表明，隔离桩挠度理论值与实测值极为接近，二者差值上部略大于下部。由此可见，所采用的分析方法和理论模型能够精确地模拟导洞—隔离桩结构体系的工作状态，可用于类似工程中结构的设计。
关键词：导洞—隔离桩；工作机理；弹性地基梁；变形分析

Mechanism of a drift-pile system and analysis of its horizontal displacement

Yao Haibo¹　 Wang Mengshu¹　 Zhang Dingli¹　 Chen Hao²
( 1. Beijing Jiaotong University，Beijing 100044，China；
2. China railway tunneling group，Beijing 100078，China )

Abstract: Based on the ground deformation data，the stress and displacement characteristics of a drift-pile system serving as an underground retaining wall is studied. The ratio of soil displacement to its corresponding displacement in passive critical state is adopted to modify the coefficient of horizontal pressure so as to describe the mechanical state more accurately. The beam and beam on elastic foundation theories are employed to simulate the behavior of the drift-pile system. The drift acts like a horizontal spring，its rigidity can be calculated via static mechanical analysis. Two models are set up to simulate the excavations at the tunnel face and at the bench，respectively. The integrated results illustrate the behavior of the system. The calculation result agrees very closes to the measured data. Nevertheless the difference in the upper part of the system is a little larger than that in the lower part.
Keywords: drift-pile system；structure behavior；elastic foundation beam；displacement analysis
E-mail：climberyao@sohu.com

基于随机需求的公交运营设计优化模型及算法

宋　瑞¹　 何世伟¹　 杨　 海²　 罗康锦²
（1．北京交通大学，北京 100044；2．香港科技大学，中国香港）

摘要：运用机会约束规划方法，研究随机需求条件下公交运营设计的优化问题。首先将公交运行情况抽象到三维网络中，通过设定车辆满载率和乘客平均等待时间两类与公交服务相关的机会约束，构造了公交时刻表设计与车辆运用综合优化的机会约束规划模型，考虑在一定的公交服务置信水平条件下的公交企业经济效益最大化问题，利用公交运营的特点和公交车辆运行的时空网络结构图进行启发式分解算法设计，给出基于蒙特卡洛模拟技术的机会约束规划检验办法，子算法中嵌入网络单纯型算法以提高求解效率。通过对北京某公交线路实际运营数据试验，对模型和算法的有效性进行验证，分析揭示出在不同乘客平均等待时间条件下车辆满载率和目标效益的关系，结果表明提出的模型与算法对改进公交运营管理质量能提供较好的辅助决策支持。
关键词：公交运营；时刻表；车辆路径；时空网络；机会约束；随机规划

Optimal transit operation plan model and algorithm with stochastic OD demands

Song Rui¹　 He Shiwei¹　 Yang Hai²　 Hong Kam Lo²
(1. Beijing Jiaotong University，Beijing 100044，China；
2. Hong Kong University of Science and Technology，Hongkong，China)

Abstract: The comprehensive optimization problem of transit operations with stochastic OD demands is studied by using a chance-constrained programming method. A chance-constrained stochastic model based on a 3-dimention time-space network is formulated to capture the coordination of transit service schedule and bus operation plan，with two chance constraints as bus loading rate and average passenger waiting time relating to transit service standards. The objective involves maximizing the transit operator’s profit with the probabilistic constraints of given service standards. A heuristic decomposition method is designed by considering the characteristics of transit operations and time-space transit network. The Monte Carlo method is employed to check whether or not the chance constraints hold. A network simplex method is inserted into the sub-algorithm for improving its efficiency. A numerical example based on a bus line in Beijing demonstrates the effectiveness of the proposed model and solution. The relationship between bus loading rate and objective value with different average passenger waiting time is analyzed. The results indicate that the model and solution could be a promising way to improve the management quality of transit operations.
Keywords: transit operation；timetable；vehicle routing；time-space network；chance-constrained；stochastic programming
E-mail：rsong@center.njtu.edu.cn

联合方式划分/交通分配模型的扩展和修正研究

王山川　 关宏志
(北京工业大学，北京 100022)

摘要：针对进行包括城市轨道交通在内的多方式（两种以上）交通需求预测时，方式划分和交通分配阶段模型存在参数不一致的问题，考虑各种交通方式在路网中的相互影响关系，提出一种交通方式分类方法。在此基础上，建立基于非集计模型的、多方式的、联合方式划分/交通分配的扩展模型，并给出该模型的等价性和解的唯一性证明及解法，最后通过一个算例验证模型的有效性。结果表明：提出的模型不仅能够满足三种及以上交通方式并存的网络的交通需求预测，而且能够有效地解决交通方式划分/交通分配两阶段参数不一致的问题。
关键词：城市轨道交通；交通需求预测；联合模型；非集计模型

Extension and modification of the combined model
of model split and traffic assignment

Wang Shanchuan Guan Hongzhi
(Beijing University of Technology，Beijing 100022，China)

Abstract: When forecasting the traffic demands of multiple modes of transportation，including urban rail transit, inconsistencies often exist between the model parameters of model split and traffic assignment. A classification method of traffic modes，which considered the interrelationships among various traffic models as well as their interactions，is presented. Based on this classification method，an expanded combined model split and traffic assignment model of multinomial modes is established，which contains the disaggregate model. The corresponding identification and algorithm are also provided. An example calculation is employed to verify the model. The results indicate that the model can not only satisfactorily forecast traffic demand including three kinds of traffic modes，but also can solve the inconsistency problem of the parameters at the stages of model split and traffic assignment.
Keywords: urban rail transit；traffic demand forecast；combined model；disaggregate model
E-mail: hguan@biut.edu.cn

路基刚度对冲击压实旧混凝土路面力学行为的影响分析

唐学军¹　 苏卫国²
（1. 上海交通大学，上海 200240；2. 华南理工大学，广东广州 10640）

摘要：以冲击压实技术处理旧水泥混凝土路面的力学作用过程为对象，采用三维有限元方法，研究冲击压实施工中不同路基刚度条件下的旧路面结构及路基之受力、变形特征。分析路基刚度改变对旧面板破裂及路基受压效果的影响；探讨冲压荷载在板下路基中的传递规律及作用深度与路基刚度的关系等问题。数值分析表明：在冲压荷载作用下，板下路基在一定深度范围内承受三个方向的压应力，其数值与传力深度均随路基刚度增大而增大；路基刚度越小，板下路基的垂直压缩量越大，所受压应力越均匀, 面板越易出现破裂；随着施工逐步进行，面板块度变小、路基刚度增大及土基所受压应力增大，这种在旧面板约束下的冲压作用正有益于不良路基实现先轻压后重压的逐步压实过程。所得结论与实际观察现象吻合。基于分析结果，提出的施工建议，将对冲击压实技术处理旧水泥混凝土路面具有一定的参考价值。
关键词：冲击压实；路基刚度；破裂稳固；有限元分析

Influence of subgrade modulus on the mechanical behaviors of existing impact-compacted concrete pavement

Tang Xuejun¹　 Su Weiguo²
(1. Shanghai Jiaotong University，Shanghai 200240，China；
2. South China University of Technology，Guangzhou 510640，China)

Abstract: Considering the mechanical process during the cracking and seating of existing concrete pavement by means of impact compaction in a rehabilitation project，the stress and deformation characteristics of the existing pavement structure and its subgrade were analyzed by using a three-dimensional finite element method. Several cases with different subgrade moduli of resilience were simulated in the FEM analyses and their mechanical influences on cracking of the slab and compacting of the soil subgrade are revealed. The relationships between the stress caused by impact load and the depth in soil subgrade were discussed. The scope of depth affected by impact load was explored for various subgrade moduli of resilience. The FEM analyses revealed several important features：(1) three dimensional compressive stresses exist in the affected scope of subgrade underneath the slab；(2)the scope and magnitude of the compressive stresses increase with the subgrade moduli；(3)the less the subgrade modulus，the more the vertical deformation and the stress are more uniform；(4)after the slab are cracked into smaller pieces，both the magnitudes of subgrade modulus and the compressive stress increase，which have positive effects on poor subgrades because of realization of first light then heavier compacting.
Keywords: impact compaction; subgrade modulus；cracking and seating；finite element method
E-mail: liangtang@sjtu.edu.cn