青藏铁路管道通风试验路基地温变化及热状况分析

基于青藏铁路北麓河试验段管道通风路基在2个冻融循环周期内的地温监测资料，分析了路基温度的发展、温度场分布特征及多年冻土的热流量变化．结果表明：通风管埋设于路堤中部的路基温度变化和发展情况与一般路基类似，路基在施工后的2个冻融周期内仍处于整体升温的过程；通风管埋设于路堤下部的路基，虽然前2个冻融循环周期内土体温度与原始状态相比同样有所升高，但开始出现逐渐降低的趋势，同时地温场的分布在横向上的对称性也比较好，在热交换方面，一般填土路基和通风管位于路堤中部的路基在施工后的前2个冻融循环周期内一直处于吸热过程，而通风管位于路堤下部的路基在经历了第1个周期的持续吸热过程后，在第2个冻融循环周期内已经开始放热。     

A hybrid indirect boundary element—discrete wave number method applied to simulate the seismic response of stratified alluvial valleys

A hybrid indirect boundary element – discrete wavenumber method is presented and applied to model the ground motion on stratified alluvial valleys under incident plane SH waves from an elastic half-space. The method is based on the single-layer integral representation for diffracted waves. Refracted waves in the horizontally stratified region can be expressed as a linear superposition of solutions for a set of discrete wavenumbers. These solutions are obtained in terms of the Thomson–Haskell propagators formalism. Boundary conditions of continuity of displacements and tractions along the common boundary between the half-space and the stratified region lead to a system of equations for the sources strengths and the coefficients of the plane wave expansion. Although the regions share the boundary, the discretization schemes are different for both sides: for the exterior region, it is based on the numerical and analytical integration of exact Green's functions for displacements and tractions whereas for the layered part, a collocation approach is used. In order to validate this approach results are compared for well-known cases studied in the literature. A homogeneous trapezoidal valley and a parabolic stratified valley were studied and excellent agreement with previous computations was found. An example is given for a stratified inclusion model of an alluvial deposit with an irregular interface with the half-space. Results are displayed in both frequency and time domains. These results show the significant influence of lateral heterogeneity and the emergence of locally generated surface waves in the seismic response of alluvial valleys.     

GPS精密定位中的海潮位移改正

根据海洋负荷潮理论，利用NAO99b全球海潮模型，计算了中国部分IGS站的海潮位移改正，并将海潮位移改正应用到GPS数据处理当中。在GAMIT软件的解算过程中，分别按加入和不加入海潮位移改正，对GPS基线分量和测站坐标分别进行了计算和比较分析。结果表明，海潮位移改正无论是对GPS基线分量还是对测站坐标，都有一定的影响。     

特定基准下的异常位移诊断

针对地壳运动和变形研究中存在的位移资料的参考基准、异常位移等问题，主要讨论了位移资料特定基准的转换和异常位移诊断的数学模型——特定基准转换模型为七参数相似变换模型，转换保持了变形体内部相对位置关系不变，并使转换后的位移矢量更能体现区域内的相对运动信息；异常位移诊断采用拟准检定法(QUAD)，在选定拟准观测的情况下，使得位移真误差具有明显的分群性；模拟算例结果显示，本文采用的线性变换模型、粗差拟准检定法都表现出很好的效果。     

Classification of artificial (man-made) ground

The legacy inherited from anthropogenic processes needs to be addressed in order to provide reliable and up-to-date ground information relevant to development and regeneration in the urban environment. The legacy includes voids as well as anthropogenic deposits (artificial ground). Their characteristics derive from former quarrying and mining activities industrial processes creating derelict ground, variably consolidated made ground, and contaminated groundwater and soils. All need to be systematically assessed to inform the planning process and provide the basis for engineering solutions. Site-specific investigation needs to be conducted on the back of good quality geoscientific data. This comes from ‘field’ survey, remotely sensed data interpretation, historical maps, soil geochemical sampling, and geotechnical investigation. Three-dimensional and, in the future, four dimensional, characterization of superficial deposits is required to reach an understanding of the potential spatial lithological variability of artificial ground and the geometry of important surfaces, i.e. the boundary conditions. The classification scheme for artificial ground outlined in this paper and adopted by the British Geological Survey, will help in achieving this understanding.     

锤击沉管碎石桩处理液化地基的工程实践

结合实际工程,对锤击沉管碎石桩加固处理液化地基的设计、施工控制及处理效果进行了系统论述,对碎石桩设计、施工中遇到的若干问题提出了建议。     

岩体断层基础加固与溶洞灌浆处理中的高压灌浆技术

阐述了在岩体断层加固和溶洞处理中的高压灌浆技术,分析了高压灌浆的作用机理,灌浆压力控制的方法,介绍了高压灌浆在水利枢纽工程上的应用效果。     

岩体边坡工程中的位移监测及分析

边坡工程的监测取决于监测人员对岩(土)体介质的认识程度和选择相应的方法和手段。通过对江西德兴铜矿大山村选矿厂东部边坡和北部楔形地质结构体稳定状况的监测,阐述了在边坡工程中位移监测的应用及有关分析。     

黄壁庄水库副坝塌坑Ⅳ76+1槽段安全监测

介绍了黄壁庄水库副坝塌坑Ⅳ76+1槽段进行的安全监测设计及根据此设计进行的安全监测实施,根据取得的监测资料解决了一直未能确定的主要变形地层的问题,为水库的加固施工和后期的运行安全提供了一定的依据。     

高层建筑深基坑支护施工技术

深圳某高层建筑原基坑已作支护,但一直废弃作鱼塘用。新的基坑支护采用土钉墙和树根桩施工,支护完成后监测结果较好,没有发生明显的位移和沉降。