The second order characteristic condition for plastic flow     

Graham Weir  Roger Young 《国际地质力学数值与分析法杂志》2003,27(15):1299-1316

In this paper the second order characteristic (discontinuous bifurcation) condition is derived for the granular flow (fully plastic) equations. This second order bifurcation equation is shown to be formally identical to the first order localization requirement during steady elastoplastic deformation provided the elastic compliance tensor is substituted for the product of the plastic multiplier with the flow Hessian. For isotropic yield and flow functions the invariant form of the characteristic condition is given in detail, as well as an alternative expression in adapted co‐ordinates. The characteristic condition can be regarded as defining a hardening function which is maximized to identify the critical angles. When the method is applied to 3D Coulomb flow, Mohr's 3D fracture plane conditions are obtained uniquely. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

浅议地勘单位的物业管理     

柯娜 《南方国土资源》2001,14(4):57-60

文章阐述了地勘单位物业管理社会化的必然性和内函 ,提出发展地勘单位物业管理的基本内容和需要解决的问题 ,最终实现以业养业 ,自我发展。  相似文献   

瞬变电磁法探测公路隧道工程中的不良地质构造     

薛国强  宋建平  武军杰  刘社华 《地球科学与环境学报》2003,25(4):73-75

为了给公路设计部门提供选线依据,运用瞬变电磁法在山西境内的某两条高速公路隧道工程设计线路段上进行探测,以查明下覆不良地质构造的发育情况.通过对瞬变电磁法的探测能力进行理论上的讨论,对不同地电断面情况下的异常体电磁响应的定性分析,得出用瞬变电磁法探测不良地质体的可行性结论.经过资料处理,查出不良地质构造赋存的位置,解释结果与钻探资料完全吻合.  相似文献   

Fast iterative solution of large undrained soil‐structure interaction problems     

Kok‐Kwang Phoon  Swee‐Huat Chan  Kim‐Chuan Toh  Fook‐Hou Lee 《国际地质力学数值与分析法杂志》2003,27(3):159-181

In view of rapid developments in iterative solvers, it is timely to re‐examine the merits of using mixed formulation for incompressible problems. This paper presents extensive numerical studies to compare the accuracy of undrained solutions resulting from the standard displacement formulation with a penalty term and the two‐field mixed formulation. The standard displacement and two‐field mixed formulations are solved using both direct and iterative approaches to assess if it is cost‐effective to achieve more accurate solutions. Numerical studies of a simple footing problem show that the mixed formulation is able to solve the incompressible problem ‘exactly’, does not create pressure and stress instabilities, and obviate the need for an ad hoc penalty number. In addition, for large‐scale problems where it is not possible to perform direct solutions entirely within available random access memory, it turns out that the larger system of equations from mixed formulation also can be solved much more efficiently than the smaller system of equations arising from standard formulation by using the symmetric quasi‐minimal residual (SQMR) method with the generalized Jacobi (GJ) preconditioner. Iterative solution by SQMR with GJ preconditioning also is more elegant, faster, and more accurate than the popular Uzawa method. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

Directions and possibilities of mathematical geology     

L. I. Chetverikov 《Mathematical Geology》1991,23(1):33-40

This paper considers the present state of mathematical geology. Three directions are recognized: applied, theoretical, and mathematical. Applied mathematical geology includes formal use of mathematics to solve problems and computer processing of data. Success is achieved by a correspondence of mathematical methods used to the nature of geological data. This correspondence can be demonstrated by purely mathematical means. Theoretical mathematical geology uses mathematics as a language of geology; however, a number of methodological problems must be solved: formalization of initial geological concepts and creation of a strict conceptual basis, substantiation of initial principles of mathematical simulation, creation of theoretical geological models, problems of elementary and coincidence in geology, and methodological substantiations of possibilities of any mathematical model to approximate geological models. The essense and significance of these problems are considered. The main task of mathematical geology is to prove its correspondence to the nature of the geological objects studied, geological data obtained, and geological problems solvable. Finally, the main problems of mathematical geology are not so much mathematical as geological and methodological.  相似文献   

辽河断陷大民屯凹陷静北潜山孢粉化石新发现     

吴炳伟张巨星  江建虹陈家敏黄淑芳  薛尚义 《地质学报》2008,82(2):165-168

静北潜山的油气勘探始于上世纪70年代初,并将钻井揭示的未见化石的碳酸盐岩和石英砂岩沉积划归中元古界长城系,沿用至今.2002年在对该区的地层研究中,首次发现了晚古生代孢粉化石,从而证实静北潜山存在晚古生代地层.本文以孢粉化石为主要依据,对潜山地层进行了重新划分,并与邻区进行对比.在此基础上对本区的构造和沉积作一讨论.  相似文献   

汶川大地震（MS 8.0）同震变形作用及其与地质灾害的关系   总被引：12，自引：2，他引：10  

付小方  侯立玮  李海兵  王宗秀  邹付戈 《地质学报》2008,82(12):1733-1746

2008年5月12日发生于四川盆地西部龙门山断裂带的汶川大地震（MS 8.0）波及半个亚洲,震撼整个中国。本文通过地震后的实地调查,对发育在龙门山断裂带上的同震地表破裂带的分布、产状、继承性复活与变形特征,以及同震变形与地震地质灾害的关系等进行了初步总结,分析表明这次汶川大地震(MS 8.0)沿北川-映秀逆冲断裂和安县-灌县逆冲断裂同时发生地表破裂,前者产生以高角度逆冲兼右旋走滑为特征的地表破裂带长约275 km,后者产生以缓倾角逆冲作用为特征的地表破裂带长约80 km。汶川大地震的同震地表破裂带分布具有分段性特征,并与地表破坏程度的分带性有着一定的内在联系,详细研究表明,同震地表破裂带的产状直接影响地表破坏程度和地震地质灾害的强度,汶川大地震（MS 8.0）沿呈高角度陡倾的北川-映秀逆冲断裂发育的同震地表变形所产生的地表破坏程度和地震地质灾害的强度比沿缓倾角的安县-灌县逆冲断裂要强。从各种类型的地震断裂来看,具有垂直运动的逆冲型地震断裂所造成的地表破坏程度和地质灾害强度比具水平运动的走滑型地震断裂要强。因此,汶川大地震发生的破裂过程和同震地表变形与地震地质灾害的关系值得深入研究。  相似文献   

TBM在不良地质洞条件下的施工技术          下载免费PDF全文

刘大军  张益忠 《探矿工程》2008,35(10):60-65

TBM掘进机以其快速、高效、安全、优质等优点越来越广泛地被应用于隧洞开挖施工中,尤其更适用于深埋超长隧洞,然而在不良地质洞段中TBM掘进缓慢,甚至有卡刀可能,反而不如钻爆法灵活,这就需要根据围岩性状采取特殊技术处理措施,辅以监控量测手段对支护方案进行验证、调整支护措施、修正设计参数等。结合辽宁大伙房输水隧洞工程,总结了在不良地质洞条件下的超前地质预报方法、不良地质段处理措施以及围岩变形监测方法。  相似文献   

滑坡体三维地质建模与可视化分析   总被引：1，自引：0，他引：1  

李明超  胡兴娥  安娜  刘杰 《岩土力学》2008,29(5):1355-1360

针对滑坡地质研究的自身特点,提出了面向滑坡地质体三维建模的NURBS-BRep混合数据结构和地质结构单元实体构造技术.通过对滑坡基础地质数据的预处理、滑坡数字地形和滑动面的三维建模、地质结构面的系统构造、地质结构体的生成和显示,形成了一套完整的滑坡三维地质模型的构建方法.将该方法应用于某水库滑坡,建立了相应的三维滑坡地质模型,并基于此模型进行了三维剖切分析、数字钻孔、等值线生成、滑块自动剖分、滑坡失稳可视化动态模拟和滑坡体方量精确计算等一系列实用的可视化分析,为滑坡稳定性的准确计算和客观评价提供了有力的支持.  相似文献   

加强技术创新服务地质调查——庆祝探矿工艺研究所成立30周年   总被引：1，自引：1，他引：0  

胡时友  彭文范  周良宗 《探矿工程》2008,35(7):1-4

为加强地质探矿技术力量,改变地质装备落后现状,经国务院批准,1978年8月8日成立了探矿工艺研究所。30年来,经过新老两代工艺所人的艰苦奋斗、刻苦钻研、勇于创新,在科研攻关、成果转化、基地建设和管理等方面都取得了可喜的成绩,为国家的地质科学事业做出了贡献,目前已成为一个“以勘查技术为基础,以承担地质调查任务和科研项目、提供勘查与监测技术方法和技术服务为手段,以服务国家经济建设、社会发展和地质工作为目标,以探矿工艺技术和地质灾害监测防治技术研发为主业”的地质调查科研机构。回顾了工艺所艰苦创业、改革进取的发展历程,对科技体制改革、专业结构调整、人事分配制度改革、地质调查和科研工作进行了总结,展示了丰硕的科研成果和强劲的科技实力;指出了工艺所在“十一五”期间地质调查和科研工作的重点领域和优先发展方向。  相似文献