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51.
龙滩水电站左岸蠕变体B区边坡位移监测分析   总被引:2,自引:2,他引:2  
结合地下水位监测与降雨量监测结果,对龙滩水电站左岸蠕变体B区边坡位移监测资料进行综合分析,认为边坡蠕变岩体位移主要发生在高程520m以上,且强风化线或蠕变岩体折断面控制着边坡岩体的变形,由于边坡排水、坡体压脚,岩体变形速率逐渐变小,目前已经基本稳定。应加强边坡强风化线或蠕变岩体折断面附近的位移监测,特别是蓄水期监测;同时要保证地表和地下排水系统的正常运行。  相似文献   
52.
A major earthquake (M=6.6) occurred on 21 June 2000, in South Iceland. This paper presents an unusual example of left-lateral strike-slip displacement recorded in a newly asphalted car park surface through a mechanically consistent pattern of open fissures and pressure ridges resulting from simple shear and rotation. Measurement of these features allows accurate reconstruction of the local deformation. The behaviour of the asphalt layer resembles that of analogue physical models, especially in terms of rotations induced by shear deformation. It is finally shown that through a wide range of scales some basic patterns associating rotation and opposite senses of strike-slip exist in the South Iceland Seismic Zone.  相似文献   
53.
深圳地区全,强风化花岗岩承载力探讨   总被引:1,自引:0,他引:1  
对《深圳地区建筑地基基础设计规程SJG1-88》中全、强风化花岗岩的划分和承载力值进行讨论,将全、强风化层各划出两个亚层,同时提出了各亚层的承载力及变形模量范围值。  相似文献   
54.
松散堆积体工程边坡变形机理分析及支护对策研究   总被引:1,自引:0,他引:1  
合理选择开挖坡比、正确认识变形破坏机理是影响松散堆积体边坡稳定性和施工安全的前提, 本文研究了西南地区某松散堆积体工程边坡的结构特征, 根据地形条件确定了合理的开挖坡比, 采用二维有限元研究了开挖边坡的变形机理并根据模拟结果确定潜在滑动面, 在此基础上, 提出支护对策。研究结果表明, 边坡由厚度达70m 的坡洪积、泥石流块碎石堆积体组成, 斜坡下部缓中部稍陡, 开挖平台位于缓坡部位, 根据地形条件结合坡体结构特征确定边坡开挖坡比为1: 0. 75; 数值模拟结果表明, 边坡变形开挖面附近及坡顶拉应力和坡体下部最大剪应力控制, 坡顶部位将首先产生拉张裂隙, 开挖边坡内部产生从坡脚部位向上发展的剪切变形, 滑面一旦与坡顶拉裂缝贯通, 边坡将产生整体失稳; 边坡采用锚拉桩、锚索框架、锚杆框架、排水相结合的综合治理措施进行支护。  相似文献   
55.
结合新疆克拉玛依三座坝线均长达5km左右的平原水库,介绍了由于地质环境影响大坝沉降和位移而建立变形监测控制网、观测方法、数据分析处理以及工作中的一些方法和经验.  相似文献   
56.
The microstructure of a quartzite experimentally deformed and partially recrystallised at 900 °C, 1.2 GPa confining pressure and strain rate 10−6/s was investigated using orientation contrast and electron backscatter diffraction (EBSD). Boundaries between misoriented domains (grains or subgrains) were determined by image analysis of orientation contrast images. In each domain, EBSD measurements gave the complete quartz lattice orientation and enabled calculation of misorientation angles across every domain boundary. Results are analysed in terms of the boundary density, which for any range of misorientations is the boundary length for that range divided by image area. This allows a more direct comparison of misorientation statistics between different parts of a sample than does a treatment in terms of boundary number.The strain in the quartzite sample is heterogeneous. A 100×150 μm low-strain partially recrystallised subarea C was compared with a high-strain completely recrystallised subarea E. The density of high-angle (>10°) boundaries in E is roughly double that in C, reflecting the greater degree of recrystallisation. Low-angle boundaries in C and E are produced by subgrain rotation. In the low-angle range 0–10° boundary densities in both C and E show an exponential decrease with increasing misorientation. The densities scale with exp(−θ/λ) where λ is approximately 2° in C and 1° in E; in other words, E has a comparative dearth of boundaries in the 8–10° range. We explain this dearth in terms of mobile high-angle boundaries sweeping through and consuming low-angle boundaries as the latter increase misorientation through time. In E, the density of high-angle boundaries is larger than in C, so this sweeping would have been more efficient and could explain the relative paucity of 8–10° boundaries.The boundary density can be generalised to a directional property that gives the degree of anisotropy of the boundary network and its preferred orientation. Despite the imposed strain, the analysed samples show that boundaries are not, on average, strongly aligned. This is a function of the strong sinuosity of high-angle boundaries, caused by grain boundary migration. Low-angle boundaries might be expected, on average, to be aligned in relation to imposed strain but this is not found.Boundary densities and their generalisation in terms of directional properties provide objective measures of microstructure. In this study the patterns they show are interpreted in terms of combined subgrain rotation and migration recrystallisation, but it may be that other microstructural processes give distinctive patterns when analysed in this fashion.  相似文献   
57.
Multiphase flow processes in unsaturated cohesive soils are often affected by deformation due to swelling and shrinking as a result of varying water contents. This paper presents a model concept which is denoted ‘phenomenological’ in terms of the processes responsible for soil deformation, since the effects of deformation on flow and transport are only considered by constitutive relations that allow an adaptation of the hydraulic properties. This new model is validated in a detailed intercomparison study with two state-of-the-art models that are capable of explicitly describing the processes relevant for the deformation. A ‘numerical experiment’ with a state-of-the-art reference model is used to produce ‘measurement data’ for an inverse-modelling-based estimation of the model input parameters for the phenomenological concept.  相似文献   
58.
在概要地讨论了辽河岩群基本地层学特征基础上,提出了构造变质岩石地层的概念,其含义为经强烈构造变形的中浅变质沉积(含火山沉积)岩系构成的岩石地层单位的一种类型。构造变质岩石地层单位是强变形、中浅变质沉积岩区1∶5万填图的基本填图单位。建议采用岩群、岩组、岩段等地层单位命名系统,强调了变形、变质、沉积综合研究方法。  相似文献   
59.
滇西北石鼓片岩变质变形特征及其划分   总被引:3,自引:0,他引:3  
李昆琼 《云南地质》2003,22(3):329-335
滇西北金沙江结合带东侧的石鼓变质岩系,可划分为石鼓岩群和巨甸岩群。石鼓岩群受区域动力热流变质作用改造,主期变形环境为中、深部构造相;巨甸岩群受区域低温动力变质作用改造,与之相伴的构造形迹属中、浅部构造相。石鼓岩群包含羊坡岩组和露西岩组,巨甸岩群可进一步划分为陇巴岩组和塔城岩组。同一岩群的岩组,变质作用、构造变形特征相同,但变质岩石组合及原岩特征却有明显差别。  相似文献   
60.
软土深基坑变形与控制技术初探   总被引:1,自引:0,他引:1       下载免费PDF全文
通过对软土深基坑变形机理与影响因素的分析,提出了基坑工程变形全过程控制的理念,探讨了控制变形的设计与施工技术方法及针对变形异常应采取的应急措施。结合工程实践,分析了软土深基坑变形的特征,应用地层损失法原理计算了墙后地表沉降量,与实测值比较,得出了该方法可以应用于工程实践的认识。  相似文献   
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