公路隧道穿越采空区治理技术研究

采空区是公路隧道典型不良地质情况之一,总结了隧道采空区处理的原则和方法。结合西山坪隧道下采空区的分布特征,分析了采空区对隧道稳定性的影响,阐述了下采空区的治理措施。     

高压旋喷桩复合地基在高层住宅楼中的应用

以郑州市某高层住宅楼工程为例,介绍了高压旋喷桩复合地基的设计计算和施工方法,经静荷载试验和建筑物沉降观测,复合地基的承载力可以满足设计要求,说明高压旋喷桩复合地基可以成功地用于高层住宅楼的建筑中.     

Lateral dynamic response of a pipe pile in saturated soil layer

This paper presents an analytical solution for the lateral dynamic response of a pipe pile in a saturated soil layer. The wave propagations in the saturated soil and the pipe pile are simulated by Biot's three‐dimensional poroelastic theory and one‐dimensional elastic theory, respectively. The governing equations of soil are solved directly without introducing potential functions. The displacement response and dynamic impedances of the pipe pile are obtained based on the continuous conditions between the pipe pile and both the outer and inner soil. A comparison with an existing solution is performed to verify the proposed solution. Selected numerical results for the lateral dynamic responses and impedances of the pipe pile are presented to reveal the lateral vibration characteristics of the pile‐soil system. Copyright © 2015 John Wiley & Sons, Ltd.     

A 3D discrete FEM iterative algorithm for solving the water pipe cooling problems of massive concrete structures

Water pipe cooling has been widely used for the temperature control and crack prevention of massive concrete structures such as high dams. Because both under‐cooling and over‐cooling may reduce the efficiency of crack prevention, or even lead to great harm to structures, we need an accurate and robust numerical tool for the prediction of cooling effect. Here, a 3D discrete FEM Iterative Algorithm is introduced, which can simulate the concrete temperature gradient near the pipes, as well as the water temperature rising along the pipes. On the basis of the heat balance between water and concrete, the whole temperature field of the problem can be computed exactly within a few iteration steps. Providing the pipe meshing tool for building the FE model, this algorithm can take account of the water pipe distribution, the variation of water flow, water temperature, and other factors, while the traditional equivalent algorithm based on semi‐theoretical solutions can only solve problems with constant water flow and water temperature. The validation and convergence are proved by comparing the simulated results and analytical solutions of two standard second‐stage cooling problems. Then, a practical concrete block with different cooling schemes is analyzed and the influences of cooling factors are investigated. In the end, detailed guidance for pipe system optimization is provided. Copyright © 2015 John Wiley & Sons, Ltd.     

再论盐源模范村喜马拉雅期斑岩铜矿床地质特征及找矿前景

该矿床具有典型斑岩铜矿特征,成岩的多期次构成复式岩体,断裂构造控制的隐爆碎裂岩筒为成矿提供了通道和沉积场所.多期次成矿,特别是次生富集作用形成达中型规模的Ⅰ号矿体,影响次生富集带发育的F7断裂带起了重要作用.总结出适合本区斑岩群特点的找矿标志和提出的找矿靶区,对开展新一轮普查找矿具有现实意义.     

不同水泥土混合桩周围土体的扰动与强度恢复

针对由深层搅拌法或高压旋喷法施工的水泥土混合桩周围土体的扰动与强度恢复的问题,采用两种常用的施工法：高压旋喷混合法（简称旋喷法）和水泥浆搅拌混合法（简称湿法）,在日本有明黏土中施工以观测周围土体力学特性的变化。测试结果表明,水泥土混合桩周围土体的扰动程度与其施工方法有关;两种不同施工方法施工后周围土体的当日强度与原状土的强度之比分别是0.42（旋喷法）和0.68（湿法）,施工30 d后,旋喷法有44 %,湿法有40 %的初始强度得到恢复。结果亦表明周围土体模量恢复要慢于强度恢复的速度。     

鲁西大井头地区隐爆角砾岩特征及其金成矿性研究

大井头地区隐爆角砾岩主要分布在大井头、归后庄和埠西桥等地,隐爆角砾岩与中生代形成的铜石杂岩体具有成因关系.结合化学分析、微量元素、激电中梯测量资料,分析了该区隐爆角砾岩的金成矿性,确定了归后庄、埠西桥为不成矿隐爆角砾岩,查明大井头隐爆角砾岩具有较好的成矿前景,并通过激电中梯测量圈定了一个极具成矿前景的靶区.     

杨庄截潜工程趾板段帷幕灌浆效果分析

杨庄截潜工程趾板段建基面以下为弱风化白云岩和含燧石条带白云岩,透水性较强,造成库水漏失严重.为解决建基面以下基岩渗漏问题,采用趾板段帷幕灌浆封堵基岩裂隙而形成防渗帷幕,以减少库水漏失.通过趾板段帷幕灌浆达到封堵基岩裂隙的目的,满足工程设计的防渗要求.     

管井井点降水的设计与施工

本文着重探讨管井井点降水的计算方法,并结合工程实例分析管井降水设计和施工中需要注意的一些问题.     

电力隧道超大直径顶管施工扰动特性研究

由于顶管工程在经济方面的优势以及控制周围环境水平的提升,而得到广泛应用,但目前顶管扰动特性方面的研究多数限于中小顶管,未考虑超大直径顶管的特殊性。对上海世博电力电缆隧道顶管施工进行了现场监测,并主要分析了水-土压力变化曲线,测试结果反映了超大直径顶管顶进5阶段的扰动特性。工程经验表明,超大直径长距离顶进成功的主要作用因素有3个：泥浆套作用、开挖面控制和姿态动态调整。最后对泥浆套在顶管中的形成过程以及扰动作用机制进行了研究,泥浆套在注入、泥膜形成以及整体发挥作用的过程中具备填充、支承、隔阻、润滑等作用。