Monitoring of Over Cutting Area and Lubrication Distribution in a Large Slurry Pipe Jacking Operation

Slurry pipe jacking was firmly established as a special method for the non-disruptive construction of the underground pipelines of sewage systems. Pipe jacking, in its traditional form, has occasionally been used for short railways, roads, rivers, and other projects. Basically the system involves the pushing or thrusting of concrete pipes into the ground by a number of jacks. In slurry pipe jacking, during the pushing process, mud slurry and lubricant are injected into the face and the over cutting area that is between the concrete pipes and the surrounding soil. Next, the slurry fills voids and the soil stabilizes due to the created slurry cake around the pipes. Fillings also reduce the jacking force or thrust during operation. When the drivage and pushing processes are finished, a mortar injection into the over cutting area is carried out in order to maintain permanent stability of the surrounding soil and the over cutting area. Successful lubrication around the pipes is extremely important in a large diameter slurry pipe jacking operation. Control of lubrication and gaps between pipes and soil can prevent hazards such as surface settlement and increases in thrust. Also, to find voids around the pipes after the jacking process, in order to inject mortar for permanent stabilizing, an investigation around the pipes is necessary. To meet these aims, this paper is concerned with the utilization of known methods such as the GPR (Ground Penetrating Radar) system and borehole camera to maintain control of the over cutting area and lubricant distribution around the pipes during a site investigation. From this point of view, experiments were carried out during a tunnel construction using one of the largest cases of slurry pipe jacking in Fujisawa city, Japan. The advantages and disadvantages of each system were clarified during the tests.     

三峡库区滑坡治理工程设计中推力荷载计算方法初探

随着三峡水利工程的逐步实施，淹没区移民及新城镇建设等人类工程活动的加剧，以滑坡为主的环境地质问题日益突出。本文从稳定系数、安全系数入手，对铁道、公路等部门常用的设计计算原理进行了研究，并由此类比分析研究了三峡区回水后或库水位正常运行条件下，滑坡治理工程设计计算方法。     

钉土相互作用的剪滞力理论分析

在深基坝支护设计中 ,对钉土作用机理存在着许多模糊认识。为此 ,本文在一定假设条件下 ,建立了钉土相互作用的剪滞力模型 ;结合实例分析对模型进行了验证 ,并对钉土相互作用机理进行了分析.     

辽西地区燕山板内造山带东段中生代逆冲推覆构造

本文厘定并阐述了辽西地区燕山中生代板内造山带东段发育的推覆构造的宏观构造格局、运动学特征、形成时代和形成过程；探讨了形成该构造体系的区域构造背景及其大地构造意义。该区的逆冲构造系统由6条主干逆冲断层组成。分布于西北和东南缘的两条最外缘逆冲断层走向为ENE，居于其间的逆冲断层呈NNE-NE，而且，向东北和南西方向这些断层具有汇合的趋势。在东北端收敛于凌源-东官营子断裂（“内蒙地轴”南缘断裂）上，而在西南端则汇拢于大屯-锦州断裂及其西延的密云-喜峰口断裂。总体上构成一个类似于双重构造（duplex)的巨型逆冲系统。该区逆冲作用始于中侏罗世之前，于株罗纪末达到高峰并基本形成了本区的推覆构造格局。本区逆冲断层系统，总体逆冲方向指向南东，与燕山板内造山带中段、西段以向北、北西逆冲为主的逆冲推覆构造明显不同。结合燕山中段发现的近东西向右行走滑断裂系统及其与本区逆冲推覆构造体系的时-空关系分析，指出本区逆冲推覆构造的形成，是没燕山东西向构造带右行走滑作用因构造方向的改变发生构造转换的结果。     

多年冻土地区L型挡土墙土压力(冻胀力)的分析与试验

为适应多年冻土区土体冻胀过程所产生的较大变形的特性, 缩短施工进程, 减少扰动时间, 在青藏铁路格拉段选择了一个试验工点进行了L型悬臂挡墙的初步验证性试验研究. 通过对L型挡墙的受力模式分析, 确定了对粗颗粒填料不考虑冻胀力的土压力设计控制值. 通过与现场实测土压力分布规律的对比, 探讨了土压力与冻胀力的关系.     

塑性岩体与逆冲构造变形关系讨论——库车坳陷西部实例分析

在冲断构造分析过程中 ,常常把塑性岩体仅仅作为滑脱层看待 ,忽略了一些地区塑性变形与冲断构造变形的复合作用。根据露头、钻井、地震等资料 ,应用平衡剖面等技术对库车坳陷西部的构造变形进行了恢复分析 ,发现库车坳陷西部的下第三系盐、膏、泥等塑性体受重力和构造应力联合作用发生了复杂的变形。以往单纯用冲断构造模式分析其成因机制 ,没能科学地反映中生界与新生界之间的变形缩短量的差异 ,通过塑性体的底辟变形和滑脱变形依存关系的剖析 ,能够恢复库车坳陷西部构造演化过程 ,进而为油气勘探提供指导。     

农牧交错带典型区农业与牧业用地互动关系研究

利用1989年和2000年的两期Landsat-TM数据和相关的统计资料以及气候数据，应用转移距阵和多元回归分析等研究方法，对地处典型农牧交错带地区的兴和县土地利用变化进行研究，结果表明：农田和草地是研究区域中最主要的土地利用类型，Landsat-TM卫星影像数据和统计数据比较一致地反映农田和草地面积的变化；农田和草地的相互转换率在各种用地相互转化中非常剧烈；农业与牧业用地的互动特征具有明显的区域差异；农业和牧业用地的互动特点是自然因素和社会经济因素同时影响的结果。     

Topography as a major factor in the development of arcuate thrust belts: insights from sandbox experiments

We have used sandbox experiments to investigate and to illustrate the effects of topography upon the development of arcuate thrust belts. In experiments where a sand pack shortened and thickened in front of an advancing rectilinear piston, the geometry of the developing thrust wedge was highly sensitive to variations in surface topography. In the absence of erosion and sedimentation, the surface slope tended to become uniform, as predicted by the theory of critical taper. Under these conditions, the wedge propagated by sequential accretion of new thrust slices. In contrast, where erosion or sedimentation caused the topographic profile to become irregular, thrusts developed out of sequence. For example, erosion throughout a hinterland caused underlying thrusts to remain active and inhibited the development of new thrusts in the foreland. Where initial topography was irregular in plan view, accreting thrusts tended to be arcuate. They were convex towards the foreland, around an initially high area; concave towards the foreland, around an initially low area. Initial plateaux tended to behave rigidly, while arcuate thrust slices accreted to them. Thrust motions were radial with respect to each plateau. Within transfer zones to each side, fault blocks rotated about vertical axes and thrust motions were oblique-slip. At late stages of deformation, the surface slope of the thrust wedge tended towards a uniform value. Initial mountains of conical shape (representing volcanoes) also escaped deformation, except at depth, where they detached. Arcuate thrust slices accreted to front and back. Where a developing thrust wedge was subject to local incision, accreting thrust slices dipped towards surrounding areas of high topography, forming Vs across valleys.Arcuate structural patterns are to be found around the three highest plateaux on Earth (Tibet, Pamirs and Altiplano) and around the Tromen volcanic ridge in the Neuquén Basin of northern Patagonia. We infer that these areas behaved in quasi-rigid fashion, protected as they were by their high topography.     

可调滞回模型的磁流变阻尼器及其试验

本文在现在磁流变阴尼器性能研究的基础上，提出了可调滞回模型的磁流变阻尼器及其试验方法，并进行理论、试验及算例分析。首先，根据恒定电流下磁流变阻尼器的阻尼力滞力特性，利用磁流变材料特性的电流（即磁场）可控特点，建立了变电流下的阻尼力滞回模型；其次，在中通过电路板控制外加电流与装置变形间的函数关系，实现了变电流调节的阻尼力滞回模型；最后，将磁流变阻尼器与橡胶隔震装置结合，形成智能磁流变隔夺装置，并对一个单自由度隔震结构进行了数值仿真分析。     

Models of passive margin inversion: implications for the Rhenohercynian fold-and-thrust belt, Belgium and Germany

Positive tectonic inversion is related to the transmission of compressional stresses along a décollement into the foreland of an orogenic zone. This stress and strain concentration in regions remote from the main orogenic front is commonly related to the presence of pre-existing rheological heterogeneities such as normal syn-depositional faults. During inversion, these pre-existing normal faults are reactivated as reverse faults. Tectonic inversion in the Rhenohercynian fold-and-thrust belt during the Variscan Orogeny shows that inversion is likely synchronous with the onset of collision in the hinterland. Here, we present the results of a simplified thermo-mechanical model (STM) which allows one to study strain partitioning between two orogenic zones. We show that, if the two orogenic zones have the same mechanical properties, the viscosity of the décollement, which links them, controls the initial strain partitioning. During subsequent finite shortening, erosional processes determine the partitioning of strain rate. The presence of a weak structure in the inverted zone and of a low-viscosity décollement leads to initial strain concentration in the inverted track rather than in the collision zone and a progressive decrease in strain partitioning between the two orogenic zones. The STM results are in good agreement with results of a 2D finite-element model. We conclude that, in the western part of the Rhenohercynian Massif, simultaneous uplift and deformation within the Mid-German Crystalline Rise (the main collision zone) and the Ardenne Anticlinorium (the inverted zone) lead to interpreting this orogenic event as a case of vice tectonic rather than the propagation of a ‘wave of folding’ towards the Variscan front, as suggested by previous authors.