上海地区超高层建筑桩基沉降计算方法探讨

本文根据已有的建筑经验,应用明特林应力分布理论及双层地基概念和土的临界应力的分析,提出了更符合实际的沉降计算方法,并论证了在第三类土层排列区(即埋深30～40mm的⑦层粉砂层)超高层桩基设置的可能性,以大大减少工程造价。     

天然地基强迫振动测试与分析

在试验块体分别为明置与埋置情形时,利用激振器对某工程场地天然地基分别进行竖向、水平回转及扭转稳态强迫振动试验。试验结果表明,埋置情形试验的动力特性参数值均大于明置情形试验相应值;同种试验情形下,地基第一振型共振频率竖向最大,水平回转向其次,扭转向最小;土的参振质量均远大于基础本身质量。     

软土地基中PHC管桩水平受荷性状的试验研究

桩在水平荷载作用下的受力性状是一个复杂的桩土相互作用过程。针对软土地集中预应力管桩受水平荷载的问题,结合工程实例,通过水平静载试验,实测得到了水平荷载作用下PHC（超长预应力）桩与土共同作用时的工作性状,分析了PHC桩受水平力作用时的内力、变形和临界承载力以及地基土的水平抗力比例系数。试验结果可为今后同类地区水平受荷桩的设计与研究提供参考。     

条形均布荷载下横观各向同性弹性地基中附加应力的分布规律

本文评述了条形均布荷载下横观各向同性弹性地基中附加应力的诸户［２］解析解和近似解，并提出了笔者的近似简化公式，该公式简明地显示出附加应力在分布规律上与各向同性地基之异同点，可供工程界方便地加以利用。     

塑料排水板处理的软土地基的分析

首先介绍了塑料排水板(PVD)加固的软土地基固结沉降计算的分析方法.该方法中提出了塑料排水板加固地基的等效竖向渗透系数的概念与计算方法.并介绍了影响分析结果的四个参数的选取方法.通过一个工程实例介绍了路堤荷载下PVD加固地基的有限元二维分析方法.结果表明所提方法可以较好地模拟实测数据.     

砂-砂砾换基防治渠道冻胀的研究

本文依据140组渠道工程上的实测数据,建立了残留冻胀率与换填比间的定量关系,据此得出了在地下水深埋和浅埋两种情况下,不同土质所要求的换填比。同时根据冻胀试验场220组粗粒土敏感性试验资料得出,当冻层与地下水距离大于或小于50cm时,应分别控制砂砾料内含土量不大于10％和5％。文末提出了防治砂砾料被含砂渠水污染及设立排水设施以保证换填防冻效果的两项措施。     

高密度电法在天津软土地基勘察中的应用

简要介绍高密度电法在天津软土地基勘察中的应用情况。分析天津软土地基的特点及地球物理前提条件，用典型实例说明高密度电法可以探查城市地下管道、了解地层起伏、探查沟坑变化、探测地基土均匀性等。发现并揭示了天津地区视电阻率与地基土物理力学指标之间的相关规律。同时估计了高密度电法可能的应用范围。     

INFLUENCE OF BUILDING EXISTENCE ON SEISMIC LIQUEFACTION OF SUBSOILS

A new simplified method is presented to evaluate seismic liquefaction potential of subsoils of buildings. Based on a review of the limited number of publications so far available, dealing with the related theme, the authors have devised the method in such a way that it is simple to handle and has clear physical insight and sufficient engineering accuracy, by taking advantage of Seed's simplified method for free ground sites and of the cone model concept well developed by Meek and Wolf in dynamics in recent years as well as by some American and German scholars in soil statics early since the 1930s. A simple example showed the reasonableness and tendency in good accord with the results of small model tests and of finite element analyses. Therefore, it would have a broad prospect of engineering application. © 1997 by John Wiley & Sons, Ltd.     

CONE模型与地基动力液化的非线性有效应力分析

在分析建筑物地基的地震（或振动）液化时,为了简化分析土壤-地基的动力相互作用,引入Cone模型,在总应力分析的方法基础上,结合了Martin等提出的孔隙水压力发展模型,并且考虑土壤发生液化的动力非线性过程中材料刚度退化的影响,提出了可以直接求解各区域的孔隙水压力的有效应力简化分析法,并进行液化可能性判别。     

Causes, effects and control of seasonal frost action in railways

Seasonally cold climate and resulting frost action set great demands to railway track substructure in order to maintain track geometry. Challenges culminate on high-speed lines, where the tolerances for roughness are the tightest. Problems may result in highly increased track maintenance and need for temporary speed restrictions. The causes of frost action can be associated with subsoil, subballast or ballast. The major concern in frost protection is to avoid the freezing of frost susceptible subsoil by using sufficient thickness of subballast and relying on non-frost-susceptible subballast material. This paper provides an overview of the main research findings on the role of ballast, subballast and subsoil in frost action. In new construction the material specifications, design procedures and construction methods have been developed to ensure adequate performance of track substructures, but special challenges exist in managing existing tracks that were not designed for modern requirements. In order to perform cost-effective and sustainable track maintenance, it is necessary to recognize the problem areas and define the root-causes of problems. For locating the problem sections and defining the causes of defects, a sophisticated analysis based on integration of track geometry and ground penetrating radar (GPR) data has been developed and is summarized in this paper.