Degradation of rock fracture asperities in unloading,reloading, and reversal     

Pooyan Asadollahi  Fulvio Tonon 《国际地质力学数值与分析法杂志》2011,35(12):1334-1346

Among the constitutive models for rock fractures developed over the years, Barton's empirical model has been widely used. Although Barton's failure criterion predicts peak shear strength of rock fractures with acceptable precision, it has some limitations in estimating the peak shear displacement, post‐peak shear strength, dilation, and surface degradation. The first author modified Barton's original model in order to address these limitations. Barton proposed his model for degradation of fracture asperities in unloading, reloading, and shear displacement reversal based on just one cyclic direct shear test. In this study, a database of results of 18 cyclic direct shear tests available in the literature was collected and analyzed. Modifications were made to Barton's original model (in terms of fracture cyclic shearing) to make it consistent with the modified model proposed by the first author. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

Explicit integration of a porosity‐dependent hydro‐mechanical model for unsaturated soils          下载免费PDF全文

Yue Zhang  Annan Zhou 《国际地质力学数值与分析法杂志》2016,40(17):2353-2382

An adaptive substepping explicit integration scheme is developed for a porosity‐dependent hydro‐mechanical model for unsaturated soils. The model is referred to as the modified σ –Θ model in this paper, which features the employment of the subloading surface plasticity and the stress–saturation approach. On numerical aspects, convex/nonconvex subloading surfaces in the σ –Θ space may result in incorrect loading–unloading decisions during the integration. A new loading–unloading decision method is developed here to solve the problem and then embedded into the explicit integration scheme for the modified σ –Θ model. In addition, to enhance the accuracy of the explicit integration, local errors from both hydraulic and mechanical components are included in the error control for each substep. A drift correction method is also developed to ensure the state point lies on the subloading surface in the σ –Θ space within a set error level. The performance of the loading–unloading decision method for the modified σ –Θ model is discussed through comparing it with the conventional loading–unloading decision method. The importance of involving the hydraulic component in the error control is also demonstrated. The accuracy and efficiency of the proposed adaptive substepping explicit integration scheme for the modified p–Θ model are also studied via several numerical examples. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

硅酸盐固溶体矿物中组分的韵律型空间分布及形成过程中的时-空自组织     

吴金平  王江海 《矿物学报》1990,(3)

本文根据熔体聚合模型和正规溶液模型,建立了非平衡条件下,在二组分硅酸盐熔体固结过程中的非平衡非理想界面反应的非线性动力学模型:对上式进行数值模拟表明,当W/RT<-2时,有三重态,并通过建立界面状态(组成)的质量守恒方程,合理地说明了硅酸盐固溶体矿物韵律结构形成的可能机理之一,寻找界面反应三重态是研究固溶体矿物韵律结构的一条相当普遍的途径。  相似文献   

似鱼形断层角砾形成机制及意义     

樊汝培 《湖南地质》1990,9(3):10-12

在湖南衡东县铅锌矿观察到一种似鱼形的断层角砾。利用单个角砾即可指示断层两盘位移方向和断层面产状。作者认为它将为变质岩区矿田构造研究、为钻孔岩心研究和矿山坑道地质研究中确定断层位移方向带来方便。  相似文献   

位移场的边界积分表达式     

刁顺  黄作宾 《地球科学》1991,16(4):459-465

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Static deformation of two welded half-spaces due to very long strike-slip dislocations     

Raj Kumar Sharma  Nat Ram Garg  Kuldip Singh 《Journal of Earth System Science》1991,100(4):379-388

Closed form analytic expressions for displacement and stresses at any point of either of the two homogeneous, isotropic, perfectly elastic half-spaces in welded contact due to very long strike-slip dislocations are obtained. Both cases of vertical and horizontal strike-slip dislocations are discussed in detail. Variation of the displacement with horizontal distance from the fault and with vertical distance from the interface for a vertical strike-slip fault is studied numerically.  相似文献   

Interaction among fractures and stress field computation of fracture systems   总被引：2，自引：0，他引：2  

张之立 《地震学报(英文版)》1994,7(1):43-54

ＩｎｔｅｒａｃｔｉｏｎａｍｏｎｇｆｒａｃｔｕｒｅｓａｎｄｓｔｒｅｓｓｆｉｅｌｄｃｏｍｐｕｔａｔｉｏｎｏｆｆｒａｃｔｕｒｅｓｙｓｔｅｍｓＺｈｉ－ＬｉＺＨＡＮＧ（张之立）（ＩｎｓｔｉｔｕｔｅｏｆＧｅｏｐｈｙｓｉｃｓ，ＳｔａｔｅＳｅｉｓｍｏｌｏｇｉｃａｌＢ...  相似文献   

西秦岭北缘断裂带新活动特征   总被引：27，自引：2，他引：27       下载免费PDF全文

滕瑞增  金瑶泉  李西候  苏向州 《地震工程学报》1994,16(2):85-90

在本文中，作者在近几年进行的大比例尺活断层地质填图工作的基础上，介绍了西秦岭北缘断裂带晚第四纪以来活动的基本待征，研究了该断裂带的空间展布情况、几何学和运动学特征、断层活动速率、古地震与地震重复周期等。结果表明，该断裂带自第四纪以来由压性逐渐演变为左旋扭动，其水平滑动速率为２．１－２．８ｍｍ／年，垂直滑动速率为０．４－０．７ｍｍ／年，地震复发周期约为５０００年。  相似文献   

软岩巷道弹塑性变形的理论分析   总被引：16，自引：0，他引：16  

刘夕才  林韵梅 《岩土力学》1994,15(2):27-36

本文采用莫尔－库仑屈服准则和非关联塑性流动法则分析了轴对称软岩巷道的变形规律。从轴对称平面应变问题的基本方程出发，导出了软岩巷道弹塑性变形的位移理论解答，并给出了现有应力与位移理论解的适用条件。通过实例计算结果表明，本文得出的位移理论解与有限元数值解相当吻合。  相似文献   

计算分层介质中位错点源静态位移场的广义反射、透射系数矩阵和离散波数方法          下载免费PDF全文

谢小碧  姚振兴 《地球物理学报》1989,32(3):270-280

本文将计算合成地震图的广义反射、透射系数矩阵和离散波数方法应用于静态问题,给出了分层介质中位错点源产生的静态位移场的计算方法。该方法保留了反射、透射矩阵方法的原有优点,通过将数值结果与解析解的对比表明,该方法具有较高的数值精度,可用于研究地震断层活动造成的地表形变。  相似文献