Some Attempts for Estimating Rock Strength and Rock Mass Classification from Cutting Force and Investigation of Optimum Operation of Tunnel Boring Machines     

K. Fukui  S. Okubo 《Rock Mechanics and Rock Engineering》2006,39(1):25-44

Summary. Tunnel face and wall collapse are common during excavations performed by tunnel boring machines (TBMs) due to the difficulty of correctly identifying the properties of the excavated rock. This identification, however, can be simplified by using the cutting force to estimate rock strength, a method that has already proved quite successful in Japanese tunnel excavations. This paper summarizes knowledge relating to the cutting force obtained through tunnel excavation experience, and the relationship between rock strength and TBM operation is discussed. Although TBM operators rely on intuition to set the cutter head speed appropriately, this decision process represents a logical method of operation that takes advantage of the variable speed capability of the cutter head. Selection of appropriate support methods for the excavated face is also a critical issue in tunnel excavation. This selection process is based on the condition of the rock, which is difficult to determine quickly and accurately during tunnel excavation. The present paper uses the excavation of two tunnels to demonstrate that it is possible to assign rock mass classifications accurately based on rock strength when boring a uniform rock type. It is also shown that the rock mass can be classified from the rock strength normalized by the uniaxial compressive strength when boring through mixed rock types.  相似文献   

东营凹陷流体动力系统研究   总被引：4，自引：0，他引：4  

刘晓峰  解习农  姜涛  张成 《地质科技情报》2006,25(1):55-59

根据东营凹陷地层孔隙流体的压力、盐度以及运移动力和流动样式,划分出3个流体动力系统:静水压力-低压淡水流体动力系统、静水压力低盐度流体动力系统、超压高-中盐度流体动力系统.超压高-中盐度流体动力系统以有效烃源岩、流体超压和盐度较高[ρ(TDS)≥35 g/L]为特征,压力驱动为主导;静水压力低盐度流体动力系统以常压、低盐度[ρ(TDS)=10～＜35 g/L]流体、运移通道和储层特别发育为特征,运移动力为盐度差和浮力;静水压力-低压淡水流体动力系统以静水压力-低压、淡水为特征,运移动力以浮力和重力为主.  相似文献   

滑坡稳定性评价及治理工程设计软件Slope Designer     

李长冬  胡新丽 《地质科技情报》2006,25(1):95-99

主要介绍了Slope Designer 1.2的设计开发思路和主要功能.该软件是基于Windows面向对象技术开发的滑坡稳定性评价与治理工程设计的一体化工程软件,采用Visual C 进行程序设计,包括稳定性分析子模块和抗滑桩设计子模块2部分,可对地震作用、暴雨等不同工况下的滑坡进行稳定性评价和推力计算,并能够对(锚拉)抗滑桩(弹性桩、刚性桩)的弯矩、剪力及侧应力进行计算,最后根据内力计算结果完成配筋计算.在三峡库区兴山县二里半滑坡的应用研究表明,该软件具有很好的工程实用性.  相似文献   

Seismic Response of Adjacent Buildings Connected with Friction Dampers   总被引：1，自引：0，他引：1  

A. V. Bhaskararao  R. S. Jangid 《Bulletin of Earthquake Engineering》2006,4(1):43-64

The effectiveness of passive energy dissipation systems to improve seismic performance of connected buildings is now well established through extensive analytical and experimental investigations. However, the performance of buildings connected with friction dampers has not been looked into. In this paper, the investigation is carried out to study the structural responses of two adjacent buildings connected with friction dampers under various earthquake excitations. A formulation of the equations of motion for the two adjacent multi degree of freedom (MDOF) buildings connected with friction dampers is presented. The numerical study is carried out in two parts, namely (i) two adjacent MDOF buildings connected with friction dampers having same slip force in all the dampers and (ii) two adjacent MDOF buildings connected with friction dampers having different slip forces in the dampers. The effectiveness of the dampers in terms of the reduction of structural responses, namely, displacement, acceleration and shear forces of connected adjacent buildings is investigated. A parametric study is also conducted to investigate the optimum slip force of the dampers. In addition, the optimal placement of the dampers, rather than providing the dampers at all the floor levels is also studied to minimize the cost of the dampers. Results show that using friction dampers to connect the adjacent buildings of different fundamental frequencies can effectively reduce earthquake-induced responses of either building if slip force of the dampers is appropriately selected. Also, it is not necessary to connect the two adjacent buildings at all floors but lesser dampers at appropriate locations can significantly reduce the earthquake response of the combined system. Further, it is also observed that the reduction in the responses when the two MDOF buildings connected with 50% of the total dampers is almost as much as when they are connected at all the floors, thereby reducing the cost of the dampers significantly.  相似文献   

A method for the transfer function matrix of combined primary–secondary systems using classical modal decomposition     

E. Heredia‐Zavoni  A. Prez‐Prez  F. Barranco‐Cicilia 《地震工程与结构动力学》2006,35(2):251-266

An iterative method is presented to compute the transfer function matrix of combined primary–secondary systems for seismic response analysis. It accounts for non‐proportional damping and dynamic interaction of the combined system. A closed form sequence is developed for the iterative computation of the transfer function matrix. Such sequence is assembled using independently the real classical mode frequencies, shapes and damping ratios of the primary system, and the natural frequency and critical damping ratio of the SDOF secondary system. The necessary and sufficient condition for convergence of the sequence is given in the paper. The method is illustrated through a couple of examples, including one of an appendix connected to a multi‐storey shear building. Convergence of the method is thoroughly analysed and peak responses are obtained using a spectral density function approach. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

Research on distinguishing method and mechanism of tidal deformation anomalies before large earthquakes   总被引：1，自引：0，他引：1  

张晶陈荣华  杨林章吉平 《地震学报(英文版)》2006,19(2):155-162

Introduction There are many researches on modulating and triggering seismic activities by tidal force in China and abroad. Heaton (1975) studied the tidal triggering of seismic activity and discovered that the tidal stress did have an obvious triggering action on the dip-slip or oblique slip great earthquakes. Tidal triggering of earthquakes has been studied for a long time in China, especially in recent years. For example, LI et al (2001) provided the relationship between the solar and luna…  相似文献   

桥台台背土压力的试验研究   总被引：10，自引：0，他引：10  

陈雪华  律文田  王永和 《岩土力学》2006,27(8):1407-1410

快速铁路桥台台后填土的填料选择、施工控制、质量监测等方面均不同于常规铁路，由于对桥台台背土压力研究并不多见，再加上影响土压力的因素比较复杂，目前的土压力理论还难以准确地反映土压力分布的实际情况。因此，结合现场试验，对快速铁路桥台台背土压力进行长时间观测，分析了土压力随时间的变化、土压力随填土高度变化以及填土完成后台背土压力的大小和分布情况。分析结果表明，台背土压力沿桥台深度方向呈非线性分布，土压力随着至桥台顶部距离的增大而增加，但到达一定深度后，随着深度的增大，土压力反而减小；土压力合力作用点要比理论上的土压力合力作用点有所上移，在0．41倍填土高度处。  相似文献   

四川广元市区周家坡滑坡形成机制及稳定性评价   总被引：3，自引：0，他引：3  

谭昌明  张远明 《中国地质灾害与防治学报》2006,17(4):25-28,33

周家坡滑坡位于四川省广元市南城区,目前局部处于不稳定状态,直接威胁城内300余户1,200余人以及环城南路过往车辆和行人安全,城内约3hm2土地被迫闲置。因此准确评价该滑坡稳定性至关重要。该滑坡由4个变形体组成,系古滑坡受建房和公路建设等工程活动影响后复活形成。滑坡所处斜坡长逾1,000m,且坡度较大,加之区域内雨季持续时间长,雨强大,持续降雨后滑体被激活。文章在分析滑坡所处地质环境条件的基础上,结合滑坡结构和变形特征分析滑坡形成机制,参考土工实验结果,采用不平衡推力传递系数法对滑坡稳定性进行评价,得出该滑坡体在天然状态基本稳定,但在饱水工况或饱水 地震工况条件下处于不稳定状态。依据上述分析评价结果,论文提出加固护坡、支挡工程、排水工程以及雨季监测等治理和防治措施。  相似文献   

发达地区县域土地集约利用时空变化分析——以福建省福清市为例     

魏慧  李永实 《福建地理》2007,(3)

采用综合评价法、聚类分析法、回归相关分析法对福清市土地集约利用的时空变化规律特征进行研究,并对其驱动因素进行深入的分析.研究结果表明:福清市土地集约利用水平具有明显的时空变化规律——1996~2005年土地集约利用水平呈分阶段性上升趋势,1996年和2005年土地集约利用在空间上呈5级分布格局,且空间分布状况变化不大.自然条件是影响土地集约利用最基础的因素,人口、经济、技术因素是造成区域土地集约利用差异的主要原因.同时,解释了土地集约利用的时空变化格局.  相似文献   

宾川县拉乌滑坡稳定性分析     

眭素刚  范柱国  马玲  徐恒  邹国富  李赛  鲍家亮 《上海国土资源》2007,(3):20-22

文章分析了云南省宾川县拉乌滑坡的形成机制,并对滑坡在不同工况下采用剩余推力法进行了稳定性计算。结果表明,持续降雨或暴雨对滑坡稳定性有很大的影响,必须加以治理。并提出了对滑坡的一些简单处理措施。  相似文献