共查询到20条相似文献，搜索用时 218 毫秒
1.
岩体中的软弱结构面、特别是软弱夹层和软弱的节理面以及基岩和建筑物的结合面或称界面(以下对这些面简称为弱面)对于水工建筑物的抗滑稳定,天然或人工岩石边坡和地下洞库的稳定性常常起控制作用. 相似文献
2.
通过对该挖方滑坡的地质条件、岩土体结构、软弱结构面特征、变形特征及监测数据的分析,并采用FLAC3D进行数值模拟,探讨川东北红层地区软弱夹层岩体边坡的破坏机制,为类似条件边坡的开挖、监测、预警和支护提供参考。 相似文献
3.
以苏州清明山滑坡为例,采用颗粒流软件PFC2D建立了滑坡体的二维数值模型,通过监测坡体表面不同部位的位移和应力变化情况,对边坡滑动的演化过程和破坏机理进行了详细的分析。数值试验结果显示该顺层边坡的失稳是一个渐进的过程,首先沿靠近坡面的一组软弱结构面发生滑动,下方滑床岩体在上覆滑体的挤压和摩擦作用下发生破碎,使滑动不断向深处发展。在前期形成的临空面和软弱结构面的共同影响下,滑坡后缘岩体产生一组近乎垂直的拉裂面,该竖向破裂面的存在有利于雨水入渗,进一步降低软弱夹层的抗剪强度参数,从而使边坡由小范围的崩塌破坏转为大范围的滑动破坏,属滑移-压致拉裂型滑坡。清明山滑坡滑移机理的研究对后续地质灾害治理有重要意义。 相似文献
4.
高陡岩质边坡稳定性三维离散元分析 总被引：3，自引：2，他引：1
某高陡岩质边坡地质条件复杂、软弱结构面发育、开挖高度大、坡度陡、临空面多,为边坡变形提供了有利的空间,边坡多处出现失稳破坏迹象。通过对边坡工程地质条件调查,岩体结构特征和边坡开挖等影响因素的分析,认为边坡变形主要发生在强风化强卸荷岩体内,受软弱结构面的控制比较明显,表现为结构面组合控制的块体变形失稳破坏模式。采用3DEC数值模拟软件,模拟了边坡开挖后坡体变形特征,数值模拟结果表明,边坡浅表层块体以及控制性块体稳定性差,可能导致边坡产生整体失稳。 相似文献
5.
6.
降雨条件下顺倾向煤系地层边坡稳定性的影响研究 总被引：2，自引：2，他引：0
煤系地层具有岩层软硬不均,层间胶结较差,风化速度快,遇水易软化,结构易破坏导致强度丧失等特点,特别是夹层中炭质泥岩或页岩具有强度低、易活化、易变性和渗透系数相对较小的特点,这决定了其对整体边坡的稳定性具有控制作用。文章分析了煤系地层边坡饱和、非饱和渗流降雨条件（降雨强度）、土性参数（夹层饱和渗透系数）以及边坡形状尺寸（坡脚、夹层倾角、夹层埋深）等因素对边坡渗流特点及稳定性的影响,发现软弱夹层与上下岩体渗透性差异性对边坡稳定性影响明显;软弱夹层埋置越浅,边坡越易失稳;降雨强度越大,边坡越易沿软弱夹层发生滑坡;并非坡脚越大降雨之后边坡的安全系数降低幅度就大,而是随着夹层倾角的增大,边坡的安全系数逐渐降低,边坡越易沿软弱夹层发生滑坡,这些认识对煤系地层边坡的设计和治理有重要的参考意义。 相似文献
7.
花岗岩残积土边坡存在较为发育的微裂隙结构面和一些软弱岩脉风化而成的软弱夹层,由于风化作用、降雨和地下水渗入等外界环境影响,裂隙中的填充物泥化和膨胀,结构面的抗剪强度迅速下降,造成边坡失稳破坏。通过对边坡破坏形式和机理的研究,得到了微裂隙引起边坡破坏的两个内外因素,外因是开挖导致裂隙处应力集中形成塑性破坏区;内因是裂隙处土体具有峰值—残余强度差异。以某含软弱夹层花岗岩残积土边坡为例,建立有限元数值模型对该边坡的变形特征进行研究,发现软弱夹层的存在不仅造成了边坡总体变形的增大,还决定了边坡失稳破坏时滑动面的位置。 相似文献
8.
风化岩体中存在软弱区,这些软弱区导致岩体的力学性能大幅度降低.现阶段往往采用地质钻孔取样对岩体中的软弱区进行定位以及性质分析.但是,由于造价以及工期方面的原因,地质钻孔数量非常有限,这些软弱区很难被有效定位,这在分析风化岩体的力学性能中造成了很大的隐患,成为边坡、基坑设计施工过程中岩体失稳的重要原因.本文介绍了一个风化... 相似文献
9.
通过系统分析边坡工程地质条件及岩体结构,采用定性分析结合有限元模拟研究了边坡变形破坏模式,并采用块体理论及极限平衡法系统分析边坡局部及整体稳定性。结果表明,切向边坡的变形破坏模式可以分为两类:深层变形破坏为受层间软弱夹层空间展布特征控制的块体失稳,浅表层破坏为局部块体失稳及强风化强卸荷带岩体沿最大剪应力带的滑移-拉裂变形。稳定性分析结果认为边坡浅表层岩体稳定性差,但发生深层破坏的可能性较小。 相似文献
10.
11.
In this paper one type of joint element –six –node isoparametric joint element for 2-D problem is introduced .The corresponding formulae used for finite element analysis has been derived and given here .
Using the program written by us several examples of calculations and comparisons have been done .The results show that such a joint element model can eb used successfully to simulate the joints ,intercalations and structural planes in rock masses and can give a more accurate results than that of the joint element ordinary used .Especially it has the obvious advantages when using it for representing the nonflat joints and wave –like form weak intercalations.
A sixteen –node isoparametric joint element model for 3-Dproblem and the corresponding formulate are also given in the paper . 相似文献
12.
13.
14.
在岩体工程的稳定分析中时间常常是一项不可忽视的因素.但是目前进行的许多非线性分析工作一般说来仅考虑了岩体、节理等应力一应变关系的力学非线性性质和强度特性,对于时间因素很少顾及.特别是根据实测的节理面、软弱夹层等的流变性质进行相应的分析的例子还很少. 相似文献
15.
In this paper ,a practical approach to rheological behavior of joints and weak intercalations in rock mass is given .In finite element analysis with this method for a rock engineering problem ,good agreement is found in a comparison of the calculated results with the deformations measured . 相似文献
16.
GJP-1程序是针对岩土力学课题而进行的空间非线性有限元分析的第一阶段成果,可用于含节理的三维弹性静力有限元分析。 GJP-1程序采用20节点等参元划分连续介质,而用18节点等参节理单元来模拟非连续面。本程序考虑了集中荷载、重力荷载、均布或不均布的作用方向为任意的面荷载、温度荷载,以及它们的各种组合作用。本程序允许各个单元有不同的材料性质。GJP-1程序具有自动划分网格,自动调整网格,和自动校核数据的功能,并提供波前法和分块三角分解解法供用户灵活选用,以便能在中小型计算机上求解比较大型的工程问题。本文列举了几个有理论解的算例,计算结果表明,本程序的计算精度是令人满意的 相似文献
17.
GJP-1 Program is used for three –dimensional elasto-static finite element analysis related to joints, which is the first stage result of three-dimensional nonlinear finite element analysis aimed at subject of rock and soil mechanics. Intact media and discontinuities are modeled by a twenty-node isoparametric finite elements and a sixteen-node isoparametric joint elements respectively, which can be subjected to nodal forces, gravity loads, uniformly or nonuniformly distributed loads acting perpendicularly or obliquely on any faces of elements properties for different elements. GJP-1 has an ability to generate and adjust meshes and to check input data autpmatically, and provides user with frotal solution and subblock triangular resolution in order to solve larger problems with medium or small computer. Several simple problems are solved with GJP-1 for illustrating and testing purposes. Comparison is made between the computational results and the theoretical solutions. 相似文献
18.
二维有限元网格的自适应剖分及程序实现 总被引：1，自引：0，他引：1
有限单元法在计算岩土力学领域已得到广泛应用。在有限元的分析计算中，前处理工作即准备计算数据耗时费力。如何简化前处理工作、实现网络自动生成对于推广有限元分析至关重要。作者在综合考虑多种算法原理的基础上，对非规则几何图形、复连通域的二维模型提出了一套新的自适应剖分算法。该算法可以同时生成三角形单元和四边形单元，还能对单元形状进行规则性调整。给出了详细的实施步骤，并编写了相应的应用程序，应用程序同时提供了对单元节点进行优化排序的功能。实际应用表明，能够高效快速地给出良好的剖分网格。 相似文献
19.
This paper presents the results of a numerical study that has been performed to investigate the different joint types that affect the moment-rotation relation and ultimate bending moment capacity of a joint. A 3D finite element method was adapted to establish elaborate numerical models of segments. To evaluate the possible differences in moment-rotation behavior between different joint types, 10 different joint types were simulated. Additionally, the effect of different joint types on behavior of a lining ring was investigated. The validity of the peridynamic simulation was tested by comparing results obtained in this paper against the results obtained in a study performed by Hordijk and Gijsbers. Observations of the results demonstrate that in a flat joint, the expanding of joint height increased the rotation stiffness of the joint in the linear branch, and accordingly, the ultimate bending moment of the joint increased. In the ring model, it was observed that the expanding of joint height led to the decreased of ring displacement and stress concentration in the joint. Whenever there were full surface contacts (contact two segment in total cross section) in the joints, the rotation stiffness of the joints in the linear branch became equal, and, as a result, the displacement in the ring model was the same in all joint types. In addition, it was observed that using a convex joint in the ring model increases the displacement of the ring. The ultimate bending moment of bolted joints was higher than that of joints without bolts, especially in the case of a negative moment. 相似文献
20.
In this study, the behaviour of shallow foundations subjected to eccentric inclined loads is presented using nonlinear elastic finite element analysis. The material non-linearity of the soil has been taken into consideration by employing the hyperbolic stress-strain model. The formulation of an isoparametric interface/joint element which is used between footing base and soil media has been presented. Tests have been conducted to determine the characteristics of soil-footing interface. Forty cases of strip footing resting on sand and subjected to eccentric-inclined load which were studied by Agrawal (1986) through model tests, have been analysed. The predicted pressure-settlement, pressure-horizontal displacement and pressure-tilt characteristics have been compared with experimental results of Agrawal (1986) and a reasonable agreement between the two has been observed. 相似文献