南华北地区石炭-二叠系砂岩和泥岩中粘土矿物的形成与转化   总被引：2，自引：0，他引：2  

管俊芳  陆琦  陈林丽  雷新荣 《西北地质》2003,36(1):74-77

区内砂岩中的粘土矿物主要是自生的高岭石、绿泥石和伊蒙混层，而泥岩中的粘土矿物是伊蒙混层和高岭石，少量绿泥石。未见蒙脱石。砂岩和泥岩中粘土矿物的转化具有相似的水介质和地温条件，都反映出在中—晚成岩期形成，而且与烃类的排出和运移密切相关。泥岩中粘土矿物转化和脱水作用为砂岩输送流体和释放溶解物质。而且泥岩中有机质的脱羟基向砂输送酸性水，促进砂岩中骨架颗粒溶解、次生孔隙的产生。  相似文献   

嵌岩桩与含沉渣桩低应变动力检测曲线理论计算方法与特征研究   总被引：2，自引：3，他引：2  

刘煜洲  刘东甲  王杰英 《物探化探计算技术》2003,25(2):97-104

根据文献[1]、[2]介绍了基桩反射波法动测正演问题的数理模型、计算方法及其通用性，并据此计算了完整嵌岩桩及有不同厚度沉渣的嵌岩桩与摩擦桩的理论曲线。提出了在一定物性参数条件下判断沉渣是否超过规定标准的方法，并给出了数个实例。  相似文献   

低应变反射波法在基桩检测中的应用实例及一些问题的探讨   总被引：5，自引：0，他引：5  

陈昌军 《华南地震》2003,23(2):85-89

根据应力波理论，介绍了用低应变反射波法在桩身完整性检测中的几个应用实例，并对检测中的一些问题作了探讨。  相似文献   

Introduction of structural aseismic research in China in recent four years     

罗奇峰  石春香  曹炳政  杨树龙  熊华  李仕栋 《地震学报(英文版)》2003,16(6):656-675

Introduction Greeting the coming of the 21st century, Professor HU Yu-xian and other Chinese scholars briefed the trend of earthquake engineering in China and aboard (HU, 1999; HU, ZHOU, 1999). The experiences and lessons learning from the destructive earthquakes in China and abroad in re-cent years, the damage action of the large velocity impulse in ground motion in near field in seis-mic design, numerous earthquake examples show that there are many weaknesses in aspects of earthquake p…  相似文献   

Evaluating foundation mass,damping and stiffness by the least‐squares method     

S. H. Ju 《地震工程与结构动力学》2003,32(9):1431-1442

This paper discusses how to use the three‐dimensional (3D) time‐domain finite‐element method incorporating the least‐squares method to calculate the equivalent foundation mass, damping and stiffness matrices. Numerical simulations indicate that the accuracy of these equivalent matrices is acceptable when the applied harmonic force of 1+sine is used. Moreover, the accuracy of the least‐squares method using the 1+sine force is not sensitive to the first time step for inclusion of data. Since the finite‐element method can model problems flexibly, the equivalent mass, damping and stiffness matrices of very complicated soil profiles and foundations can be established without difficulty using this least‐squares method. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

武汉市高层建筑岩土工程问题分析     

谭松林  江权 《水文地质工程地质》2003,(Z1)

武汉市是华中地区最大的城市,改革开放以来,兴建了许多高层建筑。高层建筑尤其是超高层建筑的主要特点是高度大、重心高、基底压力大及基础埋深大等。而武汉地区的地质条件又比较复杂,就第四纪地层而言,从最新沉积的各类软土如人工填土、淤泥类土、软塑状粘性土等,到全新世(Q4)沉积的各类砂土与卵砾石,直至晚更新世(Q3)及其以前沉积的老粘土均有分布。各类土层的厚度、深度及性质均变化较大。因此武汉地区高层建筑的岩土工程问题就显得复杂与多样,在众多复杂的岩土工程问题中,本文主要分析了比较突出的基础持力层与基础类型的确定,深基坑开挖中的边坡滑移、基坑涌水、流砂、突涌以及基坑防护等。通过对这些问题的分析,从中可以得出一些规律,对今后高层建筑的兴建具有一定的指导作用。  相似文献   

滑带土粘土矿物定向性的x射线衍射及其对滑坡的作用   总被引：6，自引：1，他引：6  

王洪兴  唐辉明  陈聪 《水文地质工程地质》2003,(Z1)

本文首先论述了粘土矿物颗粒定向排列测定的基本原理并提出粘土矿物定向性定量评价方法,然后根据实例—庙上北滑坡的滑带土粘土矿物的X射线衍射结果,进行定向性定量分析计算,得出滑带土粘土矿物颗粒的定向度为弱到中等定向,并以中等定向为主。因而在水的往返作用下,滑带土具一定的胀缩性及胀缩的不均匀性,再加上粘土矿物本身亦具有的胀缩性及胀缩的可逆性和循环性,故导致滑带土抗剪强度和结构强度不断降低,大大影响斜坡的稳定性。  相似文献   

A simple test and predictive models for assessing swell potential of Ankara (Turkey) Clay     

Zeynal Abiddin Erguler  Resat Ulusay   《Engineering Geology》2003,67(3-4):331-352

During the past three decades, damage due to swelling action of Ankara Clay has been observed more clearly in some parts of Ankara where rapid expansion of the city led to the construction of various kinds of structures. In this study, a comprehensive research program has been conducted (i) to investigate the effect of remoulding and desiccation on the swelling behavior of Ankara Clay and its swelling anisotropy, (ii) to estimate depth of active zone, (iii) to develop a simple technique in determining the magnitude of swelling based on water content of the soaked specimen after 24 and 72 h (w_max24,72), and (iv) to produce predictive models which could be used to estimate the swelling potential of Ankara Clay from its mineralogical and simply measured engineering characteristics. A laboratory testing program was carried out using both undisturbed, and remoulded and desiccated samples selected from 20 different locations. Montmorillonite was identified as being the main clay mineral present. Based on the moisture content variation with depth, the active expansive zone was considered to be about 2 m. The test results suggest that swelling pressure of the clay considerably decreases and/or dies out when the water content is greater than 30%. It is also noted that the measured lateral swelling is significantly in excess of the vertical equivalent indicating an anisotropy with respect to swelling. Statistical assessments indicate that a new parameter (w_max24,72) from a simple test, suggested in this study, is a very strong parameter for predicting swelling parameters of Ankara Clay. Based on 60 empirical predictive equations with coefficients of correlation between 0.96 and 0.66 from multiple regression analyses, w_max24,72, methylene blue value, liquid limit, dry unit weight and smectite content are the most important index and mineralogical properties to predict the swelling parameters of Ankara clay with small deviations from the measured values.  相似文献   

新疆盐渍土分散性研究     

杨昭  席福来  缪元勋  陈华  申联奇 《岩土力学》2003,(Z1)

通过研究分析盐渍土及改变盐渍含量对分散性试验的影响,认为土块试验、针孔试验对受高钠离子影响的盐渍土分散性评价是较为有效的方法。新疆土料石膏发育,环境水中Ca2+离子丰富,分散性评价最好在工程实际情况下进行。  相似文献   

闪长岩强风化带做高层建筑天然地基的可行性研究   总被引：1，自引：0，他引：1  

尚敏  王清  樊祜传 《岩土力学》2003,(Z1)

借助于中国工商银行山东省分行营业办公楼的工程实践,将常规勘察与原位测试相结合,运用野外钻探、室内试验、原位测试多种手段,对闪长岩强风化带的物理力学性质进行了测试分析和深入地研究,并通过对承载力、沉降变形的验算,得出其作为高层建筑的天然地基是可行的。实践证明,与桩基础处理方案相比,节省资金近200万元,大大加快了施工进度,减少了基础施工难度,取得了巨大的经济效益与社会效益;同时,也提出了研究岩石风化带所遇到的问题:由于采取原状试样及制样难,导致对其物理力学性质了解不够。  相似文献