利用BSTEM模型分析库岸边坡形态对其稳定性的影响     

冉冉  刘艳锋 《地下水》2011,33(2):162-165

库岸稳定性取决于最大崩塌临界机制的驱动力和抵抗力的平衡,二者的平衡又取决于库岸边坡形态、岩土组成、水流浪涌特征、植被覆盖等.边坡形态是库岸稳定性的基本条件,主要指标有坡度、岸高及坡面形态.以三峡库区忠县石宝镇段为例,利用BSTEM模拟分析库岸边坡形态对其稳定性的影响,从而得到如下结论,研究库岸坡形形态对其稳定性的影响,...  相似文献   

泥页岩储层岩石力学特性及脆性评价   总被引：7，自引：0，他引：7  

刁海燕 《岩石学报》2013,29(9):3300-3306

泥页岩储层的岩石力学特性对油气开发影响极大,进行泥页岩力学特性和脆性评价方面的研究,可以为泥页岩油钻井和压裂设计工作提供技术支撑。实验研究表明,泥页岩抗压强度与围压、杨氏模量成正相关;体积应变量随杨氏模量减小而增大,随泊松比增加而增加;泥页岩破坏在低围压下以劈裂式破坏为主,高围压时多出现剪切式破坏。泥页岩的脆性与其弹性参数和矿物组成关系密切,通过数值模拟和实验测量,综合弹性参数和矿物组分两种方法提出了一种新的脆性评价方法-弹性参数与矿物成分组合法(EP&MC Method),并实现了单井脆性评价,效果较好。脆性评价既是储层岩石力学特性分析的重要内容,也是压裂选层的重要依据。  相似文献   

SZW-1A型数字式温度计（V2004）通讯故障诊断及排除     

龚永俭  陈嵩  胡雪琪  马丽丽 《内陆地震》2013,(4):370-375

基于SZW．1A型数字式温度计（V2004）的维护管理经验和仪器组成,对SZW．1A型数字式温度计（V2004）的通讯故障原因进行了研究。结果表明,导致SZW-1A型数字式温度计（V2004）通讯故障的主要原因有网络链路故障、网络通讯接口故障和仪器主机故障3大类。针对SZW-1A型数字式温度计（V2004）常见非网络链路通讯故障的判定提出了一套诊断流程,并提出了该型号数字式温度计常见通讯故障的排除方法。这些故障的排除方法,对和SZW-1A型数字式温度计（V2004）有类似硬件组成的SWY-1A型水位仪、SWY-Ⅱ型水位仪、SWDW-1型水位地温综合观测仪等“十五”流体观测仪器的维护,有一定参考意义。  相似文献   

The Triggering Mechanism for the largest Aftershock （ Ms = 6.3 ） of the Great Luhuo Event （ Ms =7.6） in 1973     

Liu Guiping  Fu Zhengxiang  Ma Ming 《中国地震研究》2003,17(1):42-50

INTRODUCTIONInrecentyears,thestudiesontemporaryandspatialfeaturesofaftershocksaroundepicentersandtheirmechanismhavebeenanimportantpartofseismology .Theaftershocksrelatedtothestateoffaultruptureofmainshockscouldbedistinguishedasthreetypes,theyare:(1)theaftershocksalongbro kenfaultsegments;(2 )theaftershocksontheborderoftherupturebelt;and (3)theaftershocksin ducedbymainshocksthatoccurredbeyondthemainruptures.Themechanismofthefirsttypemightbetheadjustmentoftheremnantasperityinthefaultplaneofm…  相似文献   

The Demise of Place Equity in Sydney's Economic Development Planning     

Glen H. Searle 《The Australian geographer》2002,33(3):317-336

The role of planning in Sydney's economic development since the mid-1970s is explored, focusing on its role in reducing spatial disparities across the region. Planning policies during the period of each State government--Labor (1976-88), Liberal-National (1988-95) and Labor (1995-present)--are reviewed. The paper analyses a hierarchy of factors underlying the relative failure of policies to lessen disparities, notably intra-government failure to produce effective policies, the influence of prevailing ideology, local institutions and political culture, and the wider context of globalisation and the mode of capitalist accumulation. Each of these has been significant in limiting planning's role in addressing uneven development across the region.  相似文献   

鄂西北山区降雨型边坡失稳模式和评价方法   总被引：2，自引：1，他引：1  

柴波  余宏明  殷坤龙 《工程地质学报》2008,16(3):332-337

2003年6月的一次连续降雨诱发了鄂西北山区郧漫公路沿线多处边坡失稳。根据边坡岩土体的组成和结构特征,总结出了5种典型的暴雨型边坡失稳模式:浅层堆积体滑移、含软弱面顺层滑移、切层边坡水压劈裂破坏、碎裂岩似弧形追踪破坏和块裂岩楔体滑移。根据边坡破坏特点和降雨作用形式提出了相应的评价方法,认为浅层堆积体在暴雨下含水量,即85%~100%液限含水量时易发生滑移,通过平面无限斜坡评价法计算边坡稳定性;含软弱面顺层边坡及块裂楔形体均为剪切滑移失稳,采用简化的刚体极限平衡法计算其稳定性;切层边坡中陡倾裂缝经历了卸荷张开－水压开裂－贯通破坏的过程,通过Ⅰ型裂缝扩展判据评价边坡稳定性;碎裂岩边坡发生类似弧形滑移的追踪破坏,采用连续介质圆弧法计算边坡稳定性。  相似文献   

三峡库区土门子滑坡变形破坏机制分析   总被引：3，自引：1，他引：2  

孙东晖  刘建磊 《岩土工程技术》2008,22(5):267-270

在研究土门子滑坡地质环境和变形特征的基础上,对滑坡的成因机制、变形破坏模式及起动机制进行了分析。结果表明,该滑坡为前缘牵引后缘平推式,现处于整体蠕动变形局部滑移阶段,持续强降雨是诱发其失稳破坏的主导因素,针对滑坡体可能沿多个剪出口发生变形破坏等特征、提出了相应工程防治建议,对指导该类工程的设计和施工具有参考意义。  相似文献   

Performance of Counterfort Walls with Reinforced Granular and Fly Ash Backfills: Experimental Investigation     

Sutapa Hazra  Nihar  Ranjan Patra 《Geotechnical and Geological Engineering》2008,26(3):259-267

Experimental investigations on model counterfort retaining walls have been carried out to study the lateral movement of the walls and the nature of the failure modes. Mild steel plates of size 1,000 × 900 × 8 mm were used as model retaining walls and were placed in a tank of size 900 × 900 × 670 mm. Ennore sand, obtained from Madras India, and Fly ash, obtained from Panki Thermal Power Plant, India were used as backfill material. Tests were carried out both with and without reinforced backfill. Two types of loading conditions were applied: (i) line load and (ii) uniform surcharge. The shape and size of the failure wedge was studied by observing displacement of bands of colored through a Perspex plate fixed on one side of the tank. Plots of overturning moment against the rotation of a wall top show that with the increase in rotation of wall, the overturning moment decreases. The minimum value of overturning moment is taken as the limiting value. The failure surfaces obtained in different cases are linear and parabolic in shape.  相似文献   

利用锚杆轴力量测定围岩破坏区的方法   总被引：1，自引：0，他引：1  

胡玉银 《工程地质学报》1995,3(3):67-72

本文系统总结了锚杆轴力分布型式,分析了各轴力分布型式的力学机理。结果表明,在围岩不同区内,锚杆所受剪切力具有不同的特点,而且,锚杆所受剪切的特点在锚杆轴力分布中得到了反映。根据以上关系,提出了利用锚杆轴力量测确定围岩破坏区的方法。  相似文献   

Performance of an example jack-up platform under directional random ocean waves     

《Applied Ocean Research》2016

This article presents the results of nonlinear dynamic analyses that explore the effects of directionality and the random nature of ocean waves on the overall structural performance of a sample jack-up platform. A finite-element model is developed which rigorously includes the effects of the material and geometrical nonlinearities in the structure and the nonlinear soil-structure interaction. Two wave theories, NewWave and Constrained NewWave, are adopted to simulate the water surface and water particle kinematics, which are implemented in the numerical model developed. Analyses are performed for both two and three-dimensional wave models, and the results are compared in terms of the deck and spudcan foundation displacements. The results obtained from the analyses indicate that the inclusion of wave spreading can result in reductions in the deck displacements of the sample jack-up platform. The level of reduction is greater when considerable plasticity occurs in the foundation. Furthermore, the probability of failure can be significantly decreased when the wave-spreading effects are included. In addition, it is shown that the effects of wave-spreading on the response and failure of the sample jack-up is increased when wave period is decreased.  相似文献