红层软岩隧洞围岩变形破坏机制研究

红层软岩的物质组成、化学成分、物理力学性质等方面在国内外已有较系统的研究,但对软岩隧道围岩的变形破坏机理及其治理一直是工程技术人员关心问题。通过对回龙宫隧洞的地质环境分析及有限元数值计算,阐明了红层隧洞围岩的膨胀变形破坏机理,最后提出了在此类围岩中修建水工隧洞的过程中,防止围岩变形破坏的建议。     

碰撞构造:喜马拉雅-青藏高原隆起的时间与过程--第19届喜马拉雅-喀喇昆仑-西藏国际讨论会一瞥

一年一届的喜马拉雅-喀喇昆仑-西藏国际讨论会(Himalaya-Karakoram-Tibet Workshop，简写HKT)到今年已举办了19届。这个研究喜马拉雅-青藏高原地质演化的国际舞台，每年都有许多新“角色”和老“演员”出演新的“节目”，报告新的发现，交流新的思想。由于喜马拉雅-青藏高原是研究全球大陆巨型造山带形成过程与动力学的野外实验室，故这个讨论会每年的进展备受各国地学界学者关注。     

“地球动力学”的研究现状与展望——第32届国际地质大会研究成果综述

第32届国际地质大会通过按地域和构造作用过程等形式划分11个专题会场,展示了地球动力学的研究成果。其成果主要包括特提斯域构造演化及其不同阶段的块体裂解、拼合及后期改造的细节过程,地质历史中的超大陆分布和成因,俯冲—碰撞带深部构造和变质机制,安第斯山(Andes)缓倾角平坦式俯冲过程及其地壳变形和岩浆作用的响应,显微构造对动力作用过程的影响和控制,地壳和上地幔熔融、流变学和动力学意义,大洋岩石圈构造与演化,大陆地盾区构造和再活动,稳定大陆区地震,空间大地测量学和现代板块运动等方面。这些研究成果充分显示了地球动力学研究具有多学科、多手段(如古地磁、超深钻、地球物理、大地测量和GPS等)、多尺度(宏观、微观)和多时期、全面、综合、并逐步接近定时、定位和定量地探索和研究的特点,它从地球(主要为上地幔和地壳)的组成、结构构造入手,逐步认识地球(主要为地球岩石圈)的演化和动力学。     

The Frozen Soils and Devastating Characteristics of West Kunlun Mountains Pass Ms 8.1 Earthquake Area in 2001

The investigation on damages to frozen soil sites during the West Kunlun Mountains Pass earthquake with Ms 8.1 in 2001 shows that the frozen soil in the seismic area is composed mainly of moraine, alluvial deposit, diluvial deposit and lacustrine deposit with the depth varying greatly along the earthquake rupture zone. The deformation and rupture of frozen soil sites are mainly in the form of coseismic fracture zones caused by tectonic motion and fissures,liquefaction, seismic subsidence and collapse resulting from ground motion. The earthquake fracture zones on the surface are main brittle deformations, which, under the effect of sinlstral strike-slip movement, are represented by shear fissures, tensional cracks and compressive bulges. The distribution and configuration patterns of deformation and rupture such as fissures, liquefaction, seismic subsidence and landslides are all related to the ambient rock and soil conditions of the earthquake area. The distribution of earthquake damage is characterized by large-scale rupture zones, rapid intensity attenuation along the Qinghai-Xizang (Tibet) Highway, where buildings distribute and predominant effect of rock and soil conditions.     

西天山艾肯达坂组火山岩系同位素定年及其构造意义

西天山艾肯达坂地区较好发育了艾肯达坂纽红色陆相火山岩建造．它不整合在下石炭统大哈拉军山组之上,未经变形和变质，属于陆陆碰撞晚期的橄榄安粗岩系，其年龄确定是厘定从碰撞造山向陆内构造演化的关键。因此,通过16件新获得的钾氩年龄测值，确定艾肯达坂组火山岩系形成在260Ma～270Ma之间，属早二叠世，而不是过去认为的石炭纪；西天山的陆陆碰撞应在二叠纪末结束,此后进入陆内造山阶段。     

地铁隧道开挖引起地表塌陷分析

深圳富水软弱地层地铁隧道开挖中出现的工作面失稳及由此引起的地表塌陷是地铁安全施工中极其重要的方面，对施工安全、进度都有较大影响，同时也对整个工程造成巨大的经济损失。通过对深圳地铁Ⅰ期工程土建施工中全线部分暗挖标段出现的工作面失稳、地表塌陷工程实践和现场监测结果分析，特别着重对连续2次出现地表塌陷的3A标暗挖隧道研究，从隧道上覆地层物理力学性质参数、地层变形监测分析及施工工艺原因3方面阐述了地表塌陷的原因。明确提出剪切破坏线和失水空洞区的概念，确定出引发地表塌陷的主导因素为施工工艺原因。建议针对该类地层条件，应做好超前地质预报．适当调整预加固参数．加强隧道结构和地表的动态变形监测，施工技术人员做到准确了解施工现场动态，及时调整施工工艺参数，以保证隧道的安全施工。分析结果对深圳地铁Ⅱ期工程施工及类似地层条件地下工程施工提供科学预测、预防地表塌陷的方法和技术措施，达到地铁隧道施工中经济效益与安全施工的统一。     

某浅埋地下洞室围岩稳定及渐进破坏过程分析

以新疆乌鲁木齐市"世纪花苑"三期工程废弃人防地道为实例,在查明研究区浅埋洞室分布特征的基础上,结合现场及室内试验获取相关岩土体物理力学参数,利用快速拉格朗日差分分析程序FLAC研究浅埋洞室在拟建高层荷载作用下的稳定性及其破坏过程,通过系列模拟图,较真实地再现了洞室围岩变形破坏、尤其是塑性区发展变化过程。     

Crustal Electrical Conductivity Structure of Southern Tibet from Magnetoteiluric Survey

Two superwide bands of frequency magnetotelluric (MT) profiles (Yadong-Xuegula,Jilong-Cuoqin) across the Yaluzangbu suture were deployed along the west-east direction, for the research into the electrical conductivity structure in the shallow and deep crust along the west-east and north-south directions in the southern part of Tibet plateau. The main characters of the dectrical conductivity structure in this region are: (1) large-scale high resistive bodies exist near the Yaluzangbu suture surface, which extends to the maximum depth of more than 30 km. They are the reflection of the Gangdise granite; (2) small-scale conductive bodies exist in the southern part of the Yaluzangbu suture,and large-scale ones under the suture and in the northern part; (3) conductive bodies widely spread in the crust along the profiles. They are discontinuous, mainly decline to the north and become larger in scale, steeper near the suture, deeper gradually from south to north; (4) under the Yaluzangbu suture,the conductive bodies become larger in scale, more conductive gradually from west to east. These important dectrical characters are caused possibly by the India plate subduction to the north. The variation in characters of the large-scale conductive bodies from west to east may be the proof that the plate collision might cause substantial movement along the west-cast direction.     

岩石断裂破坏的机理研究

由于岩体中岩石通常处于宏观压应力状态，因此人们常认为岩石的破坏为剪切破坏。根据我们的研究，对于岩石的断裂破坏，其本质应归为微裂缝的拉张破坏。