山东临朐铁寨金矿区地球化学特征   总被引：1，自引：1，他引：0  

周斌  仲崇学 《世界地质》2000,19(2):160-166

通过对铁寨金矿区各类岩石、矿石、成矿作用及矿体的地球化学特征的研究,提出了该矿区的原生地球化学找矿模式,即该区岩浆岩、沉积岩、蚀变岩及成矿作用的地球化学标志和矿体原生晕的分带性标志.  相似文献   

夯实水泥土桩的荷载传递特性   总被引：8，自引：1，他引：7  

郭忠贤  杨志红  宋杰  康晓明 《岩土力学》2000,21(3):284-288

运用荷载传递法结合 Geddes 公式计算夯实水泥土单桩的荷载(Q)- 位移(s)曲线, 分析单桩 Q-s 曲线随桩长 l 、桩体极限强度 qu 、桩端土压缩模量 Es 的变化规律, 并研究桩身压缩、桩端阻力及位移随桩顶荷载的变化规律。  相似文献   

不同实验条件下大理岩主破裂的分数维   总被引：2，自引：0，他引：2       下载免费PDF全文

李彪  马胜利 《地震地质》1993,15(2):157-163

以大理岩为样品,在围压10～60MPa下进行了三轴压缩条件下的变形破坏实验,统计并分析了主断裂面的分维几何特征。在环境因素和介质条件相同的情况下,D值不随标本尺度变化,表明岩石破裂结构的确具有自相似性。围压是影响D值大小的一种因素,在约35MPa以下,D值随围压增加而降低;在约35MPa以上,随围压的增加而增加。提出在分析野外断层迹线的分维特征时,尚应考虑断层形成时的环境条件及其可能的随深度的变化  相似文献   

压实作用研究在沉积环境分析中的应用     

江明根 《煤田地质与勘探》1999,27(1):1-3

通过对第四系沉积物孔隙度的分析及对研究区岩矿特征、密度资料的研究,推算出不同岩性岩石厚度的压缩率和压实比。根据压实比换算出过去一定埋深范围内的原始沉积厚度,从而作出原始沉积的岩相古地理剖面图。这种剖面图可以直观地解决复杂结构的煤层对比问题,直观地分析地层沉积演化过程。   相似文献   

Shear-wave splitting of Sichuan Regional Seismic Network   总被引：1，自引：0，他引：1  

张永久  高原  石玉涛  程万正 《地震学报(英文版)》2008,21(2):127-138

Using seismic data recorded by the Chengdu Digital Seismic Network from May 1, 2000 to December 31, 2006, we obtain the dominant polarization directions of fast shear-waves at eight digital seismic stations adopting the SAM technique. The results show that the dominant directions of polarizations of fast shear-waves at most of sta-tions are mainly in nearly NE-SW or NW-SE direction in Sichuan. The dominant polarization directions of the fast shear-waves at stations located at the active faults or intersection of several active faults are consistent with the strikes of active faults which control the earthquakes used in the analysis, and are basically consistent with the directions of regional compression axis. However, several stations show that the fast shear-waves are not consis-tent with the strikes of active faults and the directions of regional compression axis, due to the influence of local complicated crustal structure.  相似文献   

Effect of fault jogs on frictional behavior: An experimental study   总被引：1，自引：0，他引：1  

ShengLi Mi  ShunYun Chen  PeiXun Liu  XiaoYan Hu  KaiYing Wang  YuanMin Huang 《中国科学D辑(英文版)》2008,51(10):1436-1445

Studying the effect of geometrically irregular bodies on the mechanical behavior of fault activity is of significance in understanding the seismic activity along a fault zone. By using rock mechanics ex- periment with medium-scale samples, we have studied the effect of fault jogs, the most common irregularity along fault zones, on frictional behavior. The research indicates that extensional fault jog can be easily fractured because of its low strength and the fractured jog has no obvious resistance to fault sliding, and the micro-fractures occurring in the jog are indicative of stick-slip along the faults. The fault zone containing extensional jogs is characterized by velocity weakening and can be described by rate and state friction law. Compressional fault jog makes fault sliding more difficult because of its high fracturing strength, but the micro-fractures occurring in the tensile areas around fault ends at higher stress level can provide necessary condition for occurrence of stick-slip along the faults before the jog is fractured and thus act as precursors of fault instability. Compression jog can be taken as a stable indicator of fault segmentation until the jog is completely fractured and two faults are linked.  相似文献   

修正剑桥模型的隐式积分算法在ABAQUS中的数值实施   总被引：5，自引：0，他引：5  

范庆来  栾茂田  杨庆 《岩土力学》2008,29(1):269-273

利用大型有限元软件ABAQUS所提供的用户材料子程序UMAT接口,针对修正的剑桥本构模型开发了隐式积分算法,并且与自动选择时间步长的增量有限元方程迭代解法相结合,对正常固结土与超固结土的三轴排水与不排水试验进行了数值模拟。结果表明,所发展的隐式本构积分算法与时间步长自动选择方法具有较好的稳定性和较高的计算精度,能够得到比较合理的数值分析结果。  相似文献   

光纤传感技术在锚杆轴力监测中的应用   总被引：1，自引：0，他引：1  

林传年  刘泉声  高玮  肖春喜 《岩土力学》2008,29(11):3161-3164

在简述了光纤Bragg光栅传感器基本工作原理的基础上,通过沪―蓉―西高速公路龙潭隧道支护锚杆轴力监测的工程应用,探讨研究了光纤传感技术用于岩土工程监测的几个重要环节--传感器选择、传感器安装、传感器标定及传感器埋设。通过现场监测获得了复杂地质条件下特长隧道支护锚杆轴力的变化特性,为光纤传感技术在岩土工程监测领域的应用积累了一定的经验。  相似文献   

Proposed methodology for building-specific earthquake loss assessment including column residual axial shortening     

Ahmed Elkady  Gerard Güell  Dimitrios G. Lignos 《地震工程与结构动力学》2020,49(4):339-355

This paper proposes methodological developments for quantifying the impact of residual axial shortening of first-story steel columns on earthquake loss estimations in steel moment-resisting frame (MRF) buildings. A new formulation is proposed that accounts for the likelihood of having to demolish a steel MRF building due to column residual axial deformations in addition to residual story-drift ratios. The formulation is informed by means of data from a comprehensive survey conducted worldwide to assess the likelihood of steel column repairability due to residual axial shortening. A practical method for quantifying column axial-shortening in parameterized system-level numerical simulations is presented. The proposed approach is illustrated by conducting economic seismic loss estimations in two case-study steel MRF buildings designed in urban California according to the current seismic design practice. It is found that when the ground-motion duration is appreciable, the examined steel MRFs are more prone to column axial-shortening than residual story-drifts at moderate to high seismic intensities. The results suggest that economic losses due to demolition may be underestimated if column residual axial-shortening is neglected from loss estimations. Limitations as well as directions for future research are discussed.  相似文献   

顺层页岩边坡稳定性离散元分析          下载免费PDF全文

张小勇  李晓军 《地震工程学报》2017,39(5):957-962

以承张高速某顺层页岩边坡工程为依托,首先采用单轴压缩模拟实验与宏观力学参数值对比的方法确定出边坡各岩土层的细观参数。进而建立其离散元模型,分析其稳定状态,并对其失稳过程进行研究。结果表明:边坡中的全风化页岩层向下滑动,并在坡脚堆积;强风化页岩层和中风化页岩层未发生滑动,滑动面为全风化页岩层与强风化页岩层的交界面。模型中出现的裂纹主要以压裂纹为主,且主要分布在全风化层,而其他两层未产生裂纹。离散元模拟结果与赤平投影法分析结果一致。该模拟结果对工程的设计、施工具有指导意义。  相似文献