A rock damage constitutive model and damage energy dissipation rate analysis for characterising the crack closure effect     

Tao Wen  Chenggang Yang  Xianlong Yi 《Geomechanics and Geoengineering》2018,13(1):54-63

Due to the insufficiency of the previous damage constitutive model for rock, an improved damage mechanics model for rock is proposed with characterising the crack closure effect. Otherwise, the effective methods of determining the model parameters and crack closure coefficient are proposed. The results represent that the model can reflect the damage evolution of rocks in the deformation process in the crack closure stage and this improved model is more reasonable than the previous model. Crack closure coefficient also has great effect on distribution parameters. The calculation formula of damage energy dissipation rate considered that crack closure effect is derived and the relationships between damage energy dissipation rate and crack closure coefficient are analysed. Crack closure coefficient has great effect on damage dissipation energy rate. Damage energy dissipation rate increases with the decrease of crack closure coefficient and damage energy dissipation rate increases quickly in the post-peak stage.  相似文献   

Fatigue crack growth investigation on offshore pipelines with three-dimensional interacting cracks     

《地学前缘(英文版)》2018,9(6):1689-1697

Due to high cost of full-scale experimental setup, this study presents a numerical model on fatigue behaviours of offshore pipeline with multiple coplanar cracks under cyclic tensile loadings. The validation on numerical results is made by other researchers' experimental results, and significant parameters affecting fatigue crack growth are studied.  相似文献   

Modeling of dynamic cohesive fracture propagation in porous saturated media     

A. R. Khoei  O. R. Barani  M. Mofid 《国际地质力学数值与分析法杂志》2011,35(10):1160-1184

In this paper, a mathematical model is presented for the analysis of dynamic fracture propagation in the saturated porous media. The solid behavior incorporates a discrete cohesive fracture model, coupled with the flow in porous media through the fracture network. The double‐nodded zero‐thickness cohesive interface element is employed for the mixed mode fracture behavior in tension and contact behavior in compression. The crack is automatically detected and propagated perpendicular to the maximum effective stress. The spatial discretization is continuously updated during the crack propagation. Numerical examples from the hydraulic fracturing test and the concrete gravity dam show the capability of the model to simulate dynamic fracture propagation. The comparison is performed between the quasi‐static and fully dynamic solutions, and the performance of two analyses is investigated on the values of crack length and crack mouth opening. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

Cracking risk of partially saturated porous media—Part II: Application to drying shrinkage     

Bernhard Pichler  Luc Dormieux 《国际地质力学数值与分析法杂志》2010,34(2):159-186

Drying of deformable porous media results in their shrinkage, and it may cause cracking provided that shrinkage deformations are hindered by kinematic constraints. Herein, we focus on slow drying of an initially water‐saturated sample of a microheterogeneous poroelastic material damaged by parallel mesocracks. The cracking risk is analyzed by means of the thermodynamics‐based microporoelasticity model described in the companion paper (Part I), which is extended toward consideration of the hierarchical organization of cracked argillite. Drying of a material sample is studied in a framework where macrodisplacements in direction of the crack normal are blocked, while elsewise macrostress‐free boundary conditions prevail. The model implies that the opening/closure behavior of the cracks is governed by an effective pressure, in which the average crack (under)pressure, making the crack opening smaller, competes with the average micropore (under)pressure that makes the crack opening larger. The driving force for crack propagation is a quadratic function of this effective pressure. The model proposes that if drying shrinkage deformations are hindered by kinematic constraints, onset of cracking becomes possible once air entry into the cracks is observed. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

断裂力学在冰工程中的应用     

李锋  马红艳 《冰川冻土》2010,32(1):139-150

冰工程对于断裂力学是一个相对较新的应用领域.对不同工程领域中广泛存在的涉冰断裂力学问题进行了列举归纳,然后从冰的自然特性诸方面论证了冰工程分析中引入断裂力学方法的必要性及其适用性,最后综述了主要的研究成果和进展.  相似文献   

内宜高速K43+200～256段边坡治理措施          下载免费PDF全文

谢元玉  刘文高  姚海平  张云江 《探矿工程》2009,36(2):72-74

介绍了内宜高速公路K43＋200～256段边坡的治理方案、施工措施。该边坡的4个危岩体除了都采取预应力锚索外,还针对不同危岩体的特征采取了不同的治理措施：W 1预应力锚索＋裂隙封填;W 2预应力锚索＋岩腔封砌;W 3预应力锚索;W 4预应力锚索＋危岩体支撑。经过两年多时间的考验,证明该治理方案和措施是合理的。  相似文献   

福建莆田某建筑开裂的基础补强     

庄清泉 《探矿工程》2009,36(9):64-66

某建筑建成不久,底层填充墙及基础梁就产生了开裂,开裂原因为桩基承载力达不到设计要求、采取的基础梁加大补强方案因地基土固结而失效、淤泥固结产生的负摩阻力加剧了桩基下沉等,在原因分析后采用了加大基础梁截面尺寸、并在基础梁下增设锚杆式静压桩进行补强,有效地修复了裂缝,取得了预期效果。  相似文献   

北京市平原区北部孙河断裂的地热地质特征   总被引：3，自引：1，他引：2  

柯柏林 《现代地质》2009,23(1)

依据北京孙河断裂区的重力、电阻率测深及可控源音频大地电磁测深(CSAMT)等勘查资料的推断解释,结合多眼地热井钻探揭露的地热地质成果,认为孙河断裂是一条宽3 km左右的断裂带。地热地质构造剖面揭示孙河断裂具有多期活动性,晚侏罗世以来至少发生过两期先逆后张性质的构造活动。剖析了孙河断裂对后沙峪地热田侏罗系火山岩构造裂隙热储地热地质条件的控制作用,进一步分析了孙河断裂带区域的地热地质条件,认为后沙峪地热田西南部是构造凸起型储热构造,北西向延伸的孙河断裂带区域是后沙峪地热田的地热资源富集区。  相似文献   

中国大陆北西—北北西向断裂系统与强震     

冯希杰 《地球科学与环境学报》1988,(3)

本文论述了中国大陆北西—北北西向断裂系统的分布和发育特征及其与强震间的关系。该断裂系统呈带状断续分布,是新的一次具有普遍意义的大陆地壳运动所造成的结果。其特点是发育规模较小、延伸较短、处于幼年期初破裂阶段、状态不稳定、断裂易扩张、活动性强等。它们控制着大陆现代中、强地震活动,中国大陆近代发生的一系列大地震多与大陆北西—北北西向断裂系统的活动有关。  相似文献   

Comparison of the radiated fields generated by the fracture of a circular crack and a circular asperity     

Shamita Das 《Geophysical Journal International》1986,85(3):601-616

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