层状横观各向同性地基上刚性条形基础动力刚度系数

采用间接边界元方法（IBEM）研究了层状横观各向同性（TI）地基上明置条形基础平面内动力刚度系数。首先,在波数域中求解TI介质动力平衡方程,建立了TI土层和TI半空间的精确动力刚度矩阵,并通过集整土层和半空间刚度矩阵,求得层状TI地基整体动力刚度矩阵。然后,采用刚度矩阵方法求得层状TI地基表面均布荷载动力格林函数。最后,由基础与地基表面的混合边界条件求得明置条形基础的平面内动力刚度系数。均布荷载动力格林函数的引入克服了传统边界元方法的奇异性问题,同时,精确动力刚度矩阵的引入使得方法不受土层厚度的限制。通过与已有结果比较验证了方法的正确性,并以均匀TI半空间地基、单一TI土层地基和多TI土层地基上明置基础为例进行了数值计算分析,探讨了TI参数、振动频率和土层对刚度系数的影响。研究表明,土体TI参数对刚度系数有着显著的影响,尤其是层状TI地基中刚度系数的峰值频率和峰值十分依赖于TI参数的变化;逆序地基与正常序列地基上基础刚度系数差异明显,逆序地基对应刚度系数随频率振荡剧烈且数值较大。     

横观各向同性弹性半空间非轴对称问题解析解

基于地基土存在着固有各向异性和诱发各向异性 ,本文采用横观各向同性弹性体模型模拟地基半空间 ,将Love位移函数推广到半空间 ,得到位移与位移函数之间的关系 ;然后经过Hankel变换得到非轴对称问题位移、应力的一般解。本文的一般解经过退化 ,得到的轴对称弹性半空间解与经典解吻合。     

Assessing artificial neural network performance for predicting interlayer conditions and layer modulus of multi-layered flexible pavement

The objective of this study is to evaluate the performance of the artificial neural network (ANN) approach for predicting interlayer conditions and layer modulus of a multi-layered flexible pavement structure. To achieve this goal, two ANN based back-calculation models were proposed to predict the interlayer conditions and layer modulus of the pavement structure. The corresponding database built with ANSYS based finite element method computations for four types of a structure subjected to falling weight deflectometer load. In addition, two proposed ANN models were verified by comparing the results of ANN models with the results of PADAL and double multiple regression models. The measured pavement deflection basin data was used for the verifications. The comparing results concluded that there are no significant differences between the results estimated by ANN and double multiple regression models. PADAL modeling results were not accurate due to the inability to reflect the real pavement structure because pavement structure was not completely continuous. The prediction and verification results concluded that the proposed back-calculation model developed with ANN could be used to accurately predict layer modulus and interlayer conditions. In addition, the back-calculation model avoided the back-calculation errors by considering the interlayer condition, which was barely considered by former models reported in the published studies.     

高层剪力墙结构层间位移角的调整

对高层剪力墙结构层间位移角的构成进行了理论解析,并结合工程实例,给出了在风荷载作用下高层剪力墙结构最大弹性层间位移角调整的若干方法,为同类问题的研究积累了经验。     

滑移减震砌体结构的发展

通过对我国滑移减震砌体建筑结构发展概况的介绍,总结了目前我国滑移减震砌体建筑结构取得的一些成果及成就,最后提出滑移减震砌体建筑结构在我国有着广阔的应用前景,值得推广使用。     

DQEM for large deformation analysis of structures with discontinuity conditions and initial displacements

A nonlinear mathematical model of the large deformation analysis of beams with discontinuity conditions and initial displacements is first formulized by the arc coordinates. The differential quadrature element method (DQEM) is applied to discretize the nonlinear mathematical model, and an effective method of applying DQEM to analyse the large deformation of structures with discontinuity conditions of multivariables is presented. A set of DQEM discretization equations are obtained. Then, the Newton–Raphson method is used to solve the system of nonlinear algebraic equations. As applications, some numerical examples in engineering are presented, which include the large deformation analysis of beams, frames, piles with elastic joints. The obtained results are compared with those in the existing literatures. The numerical results show that the model and the method presented in this paper may be widely applied to solve the problems of large deformation of structures with discontinuity conditions in engineering; also the method has the advantages of little amount in computation, good stability and convergence and so on.     

横观各向同性土——半封闭隧道衬砌相互作用分析

土体在沉积过程中存在各向异性,将土体视为各向异性体更为合理。考虑土体和衬砌的相互作用,基于饱和多孔介质理论和弹性理论,在频率域内研究了简谐荷载作用下横观各向同性土——半封闭圆形隧道衬砌简谐耦合振动。通过衬砌内边界应力连续以及土体和衬砌界面处应力和位移协调,得到了饱和横观各向同性土和衬砌的位移、应力和孔压解析表达式。利用衬砌中流体速度和土体中流体速度相等,建立了隧道部分透水边界条件,得到了待定系数的具体表达式。数值算例分析了土体和衬砌物性和几何参数的影响,表明：横观各向同性面内的弹性模量对系统动力响应影响较大,而垂直于各向同性面内的弹性模量对系统动力响应影响较小。另外,相对渗透系数和衬砌厚度对响应幅值有很大影响,而衬砌泊松比对响应幅值影响较小。     

框架结构后张法有粘结预应力板的施工

结合工程实例,详细介绍了框架结构后张法有粘结预应力技术的工艺流程及具体施工要点,实践证明,该工程采用有粘结预应力技术,满足了工程的功能和使用要求,取得了显著的经济效益。     

一对边固定一对边自由夹层板的抗弯分析

对夹层板的抗弯性能进行了分析,求得了夹层板的抗弯挠度公式,通过假设面层内的应力呈线性分布而提出了计算夹层板的抗弯刚度公式的方法,并与ANSYS计算结果进行比较后,得出了一些有益的结论。     

有粘结预应力结构梁施工工法应用与研究

结合工程实例，对有粘结预应力在施工中的应用进行了简要的阐述，并提出了有粘结预应力梁的施工工艺控制要点和几点心得体会，实践证明有粘结预应力技术有诸多优点，可进一步推广应用。     

坝基不同倾角软弱夹层的破坏模式及D-C模型参数研究

坝基岩体中的软弱夹层对抗滑稳定影响重大,因此对其破坏模式及本构模型参数的研究具有重要意义。采用软弱夹层重塑样进行三轴压缩试验,下部未泥化部分采用泥化部分土掺入20%水泥代替,上部采用泥化部分土制样,泥化部分与未泥化部分交界面分别制成0°,30°,45°,60°倾斜面并作粗糙处理模拟实际界面特性。试验结果表明:含不同倾角结构面的软弱夹层试样临界角范围为58.3°～61.7°,当结构面倾角介于临界角范围之内时,软弱夹层试样沿结构面破坏,当结构面倾角位于临界角范围之外时,软弱夹层试样在上部泥化部分土中破坏;对软弱夹层试样三轴试验ε((σ_1-σ_3))–ε_1关系曲线进行线性拟合,结果表明,随围压增加,试样初始切线模量及极限破坏强度均增加,根据试验结果得出了相应的D-C模型参数并将其应用于坝基抗滑设计中,取得了良好效果。本研究成果对坝基软弱夹层的抗滑设计及同类软弱夹层工程性质的研究具有一定参考价值。     

建筑结构加固改造技术研究

深入分析了房屋建筑结构进行加固改造的原因,提出了增加截面、植筋、注浆及增补受拉钢筋等房屋建筑结构加固方法,以期通过加固改造,提高建筑的安全性与可靠性,确保建筑的正常使用。     

真实火灾下足尺冷成型钢复合剪力墙结构耐火性能试验研究

冷成型钢复合剪力墙结构采用冷成型钢管混凝土边柱、半刚性连接节点、组合楼盖体系和外填充式夹心组合墙体等构件,具有整体连接性强、抗震性能优越等优势.其耐火性能研究是该结构在我国推广应用的研究重点之一.为此,建造了3栋平面尺寸为7.2m×7.2m、层高3m的单层冷成型钢复合剪力墙结构模型房屋,并对其进行了不同火灾工况下的足尺...     

大吨位钢结构模块整体提升及滑移安装关键设计和施工技术

该文介绍利用同步液压控制系统技术实现大吨位钢结构模块整体提升、滑移安装工艺,并重点阐述了该工艺的关键设计方法、施工要点,总结了该安装工艺存在需改进和注意的方面,为同类大吨位整体安装工程提供了可参鉴的实例。     

Analogy of TE waveguide and vibrating plate with sliding edge condition and exact solutions

Presented herein is a proof that the TE (transverse electric) waveguide problem is analogous to the vibration problem of thin plates with zero slope and zero twisting moment at the freely sliding edges in the vertical (transverse) direction. This analogy is confirmed because of the mathematical similarity of the governing equations and the boundary conditions of the two problems. We also present exact solutions for these two analogous problems for various domain shapes. The exact solutions are very useful for checking the validity, convergence and accuracy of numerical methods for solving the Helmholtz equation.     

单层钢结构厂房的改造与加固

通过对四连跨单层钢结构厂房其中一跨的改造工程,对原厂房结构进行了计算分析,综合考虑施工、造价等因素,提出了具体的改造方案,经计算改造后厂房的结构符合规范要求,改造后的厂房达到了良好的技术与经济效果。     

对安定性不合格混凝土结构加固的条件及方法

针对使用安定性不合格的水泥给工程质量带来的隐患和发生此类质量事故时只能采取拆除结构来处理的难题,通过分析水泥安定性不合格的成因及其对混凝土结构强度的影响,提出了加固该类问题结构应满足的基本条件和加固方法。     

我国钢结构建筑的现状及发展趋势

介绍了钢结构建筑在中国的发展状况,分析了钢结构建筑的特点和优势,指出了我国钢结构建筑存在的差距,在此基础上展望了今后的发展趋势,指出钢结构住宅绿色环保,具有广阔的应用前景。