共查询到20条相似文献，搜索用时 15 毫秒
1.
Thebasicstressvariablesintheconstitutivemodelde velopedbyAlonsoetal[5] aresoilnetstressandsoilmatricsuctions ,whicharedefinedby σ″ =σ -ua (1) s=ua-uw (2 )whereσisthetotalstress,uwistheporewaterpressureanduaistheporeairpressure . Thenetmeanstresspanddeviatoricstressqarede finedas p =σ1+2σ33-ua (3) q =σ1-σ3(4 ) Asgenerallyregarded ,thesoilsuctioniscomposedoftwoparts ,matricsuctionandosmosissuction .TheosmosissuctionisneglectedoriginallyinAlonsoetal′smodelandhe… 相似文献
2.
基于沸石的微孔吸附特性,以沸石为中间介质研究模拟制备含气软土沉积物的方法;通过沸石对CH4、N2、CO2和H24种不同气体的吸附/脱附试验,探讨了沸石掺量与置换气量之间的关系,利用CT扫描试验检验了所制含气效果;基于微型十字板剪切试验,分析了土体不排水剪切强度与沸石掺量之间的关系.实验结果表明:在同等条件下,沸石掺量与... 相似文献
3.
Progressive failure analysis of slope with strain-softening behaviour based on strength reduction method 总被引：1，自引：0，他引：1
Based on the strength reduction method and strain-softening model,a method for progressive failure analysis of strain-softening slopes was presented in this paper.The mutation is more pronounced in strain-softening analysis,and the mutation of displacement at slope crest was taken as critical failure criterion.An engineering example was provided to demonstrate the validity of the present method.This method was applied to a cut slope in an industry site.The results are as follows:(1) The factor of safety and the critical slip surface obtained by the present method are between those by peak and residual strength.The analysis with peak strength would lead to non-conservative results,but that with residual strength tends to be overly conservative.(2) The thickness of the shear zone considering strain-softening behaviour is narrower than that with non-softening analysis.(3) The failure of slope is the process of the initiation,propagation and connection of potential failure surface.The strength parameters are mobilized to a non-uniform degree while progressive failure occurs in the slope.(4) The factor of safety increases with the increase of residual shear strain threshold and elastic modulus.The failure mode of slope changes from shallow slip to deep slip.Poisson’s ratio and dilation angle have little effect on the results. 相似文献
4.
5.
Richard J. Jardine 《浙江大学学报(A卷英文版)》2011,12(1):1-14
An integrated approach to geomaterial characterization is advocated that combines geology, in-situ testing, fabric studies, routine index experiments and advanced laboratory testing. It is shown that advanced laboratory testing can explore features such as kinematic yielding and anisotropy in stiffness or shear strength that would otherwise be impossible to quantify. A detailed study performed in London clay at the new Heathrow Terminal 5 site is used to illustrate the arguments made. It is shown that the London clay has strong anisotropy in stiffness, is highly non-linear over the strain range of engineering interest, has markedly anisotropic shear strength characteristics and exhibits a pronounced degree of brittleness. These features can impact significantly on the practical design and analysis of civil engineering works including shallow and deep foundations, tunnels and excavations, and the stability of slopes. 相似文献
6.
The effects of stabilizing piles on the stability of an embankment slope are analyzed by numerical simulation. The shear strength reduction method is used for the analysis, and the soil - pile interaction is simulated with zero-thickness elasto-plastic interface elements. Effects of pile spacing and pile position on the safety factor of slope and the behavior of piles under these conditions are given. The numerical analysis indicates that the positions of the pile have significant influence on the stability of the slope, and the pile needs to be installed in the middle of the slope for maximum safety factors. In the end, the soil arching effect closely associated with the space between stabilizing piles is analyzed. The results are helpful for design and construction of stabilizing piles. 相似文献
7.
许多相关研究显示,含有植生根系补强的土壤会增加土壤的凝聚性和剪力强度．当穿过滑动面的根系贯入深度越深,则对于增加土壤剪力强度的功能越大．基于根力模式之研究,植根对土壤剪力强度增量之计算,已呈现明朗而具体化．本研究除应用文献【1】中学者Waldron的根系力学理论外,亦采用文献【2】中陈等人及文献[3】中游等人所提出之根系力学修正模式来估算土壤抗剪强度增量,分析结果显示,考虑植根密度变化与合理之剪力带发展机制模拟,确能得到较准确之评估结果． 相似文献
8.
9.
INTRODUCTION Adequate information on dynamic soil proper-ties, especially dynamic shear modulus and dampingratio, is essential for accurate computations of groundresponse and soil-structure interaction problems.Many experimental investigations carried out onsandy soils through resonant column test or improvedcyclic triaxial test in early studies (Hardin and Richart1963; Hardin and Black, 1968; Drnevich and Richart,1970; Seed and Idriss, 1971; Kokusho, 1980) showedthat the small … 相似文献
10.
朱丽娟 《杨凌职业技术学院学报》2011,10(4):4-6
降雨入渗是非饱和黄土边坡失稳的主要诱发因素,滑坡与降雨有着密切的关系。黄土边坡稳定性问题越来越引起岩土工程界的重视,降雨对边坡的稳定性影响的研究还不尽完善。本文浅析了非饱和黄土边坡雨水入渗及稳定性研究的现状,均为某一实例边坡,尚缺乏对边坡问题的系统研究。基于此,本文在前人的基础上研究了坡高、坡度、干密度、含水量等因素影响下黄土边坡内水分场的分布规律,而且进一步对不同因素影响下的黄土边坡的安全系数进行了计算分析。 相似文献
11.
提出岩质边坡沿软弱结构面滑移-剪切的三维稳定分析方法。在分析模型中,下滑体沿滑动面下滑,在其他的面上则产生剪切破坏。在结构面上满足莫尔库伦破坏准则,把剪切面上的摩阻力向下滑方向投影,由下滑体的力学平衡条件求解出未知力,通过迭代可以求得稳定系数。同时推导了摩阻力倾向与倾角的计算式,编制了相应的程序,并利用这个程序,研究了边坡长度、岩层与坡面夹角等因素对边坡稳定系数的影响,比较了三维分析与二维分析的差别。 相似文献
12.
边坡稳定分析中的两类有限元方法比较研究 总被引：1，自引：0，他引：1
基于滑面上应力分析法和强度折减法是边坡稳定有限元分析方法中两类主要的方法.本文对这两种方法进行了探讨.在算例对比分析中,基于非关联流动法则,采用与经典摩尔-库仑准则相匹配的等效D-P准则,在平面应变条件下,对天然边坡的稳定性进行了对比研究工作,并同传统极限平衡方法进行比较.研究表明,两类有限元方法得到的安全系数大小以及相应滑动面形状和位置均一致. 相似文献
13.
Slope stability hazard management systems 总被引：2，自引：0，他引：2
FREDLUND Delwyn G 《浙江大学学报(A卷英文版)》2007,8(11):1695-1711
Weather-related geo-hazards are a major concern for both natural slopes and man-made slopes and embankments. Government agencies and private companies are increasingly required to ensure that there is adequate protection of sloping sur- faces in order that interaction with the climate does not produce instability. Superior theoretical formulations and computer tools are now available to address engineering design issues related to the near ground surface soil-atmospheric interactions. An ex- ample is given in this paper that illustrates the consequences of not paying adequate attention to the hazards of slope stability prior to the construction of a highway in South America. On the other hand, examples are given from Hong Kong and Mainland China where significant benefits are derived from putting in place a hazard slope stability management system. Some results from a hazard management slope stability study related to the railway system in Canada are also reported. The study took advantage of recent research on unsaturated soil behaviour and applied this information to real-time modelling of climatic conditions. The quantification of the water balance at the ground surface, and subsequent infiltration, is used as the primary tool for hazard level assessment. The suggested hazard model can be applied at either specific high risk locations or in a more general, broad-based manner over large areas. A more thorough understanding of unsaturated soil behaviour as it applies to near ground surface soils, along with the numerical computational power of the computer has made it possible for new approaches to be used in slope hazard management engineering. 相似文献
14.
路堑岩质边坡具有规模大、数量多、参数获取困难、治理难度大等特点,历来是线路工程中的研究热点.为了解决路堑岩质边坡的稳定评价问题,建立边坡稳定性的模糊综合评价体系,可供同类工程借鉴.根据路堑岩质边坡的特点,以系统全面性、简明科学性、相对独立性及灵活可操作性为原则,选取合理的边坡稳定性评价指标,建立边坡稳定性的模糊综合评价体系,运用层次分析法确定评价指标的权重,建立了路堑岩质边坡的稳定性分级模型.以某国道辅线K57+411～K57+536段边坡为例,运用该模型对其稳定性级别进行了模糊综合评判分级,其结果为不稳定,与规范法的评价结果一致,表明该方法是合理实用的. 相似文献
15.
包太 《重庆大学学报(英文版)》2003,2(1)
1. Introduction At present, the construction of large-scale reservoirworks has given rise to many large-scale reservoirareas, the stabilization of slopes in these reservoirdistricts will be influenced by water waves. Thecirculating hydraulic loading caused by the waveproduces a great force on the slope, and especiallyforms a vibration wave force on the boundary of water surface and the slope earth, and even breaks the water-soil interface, leading to the excess pore pressurechanging along diff… 相似文献
16.
INTRODUCTIONTheTianzilingwastelandfillbuiltin 1991toproperlydisposeofmunicipalsolidwaste(MSW)hasadesignedservicelifeof13years.Itwasfilledstagebystageatthebeginningoftheelevationof 50 .5m .Bynow ,thelandfillhasreachedthelevelof 10 2 .5m ,whichex ceedst… 相似文献
17.
ZUO Chang-qun CHEN Jian-ping 《浙江大学学报(A卷英文版)》2007,8(2):270-274
INTRODUCTION Jing-Yi Expressway (95 km) is the Jingmen-Yichang section of the Hangzhou-Lanzhou Ex-pressway line. The embedment slopes along the lineare mainly expansive slopes causing many incon-veniences for engineering. With longtime exposure,water accumulated in widespread sections because ofbad drainage measures, and constructions collapsed.In this work, a selected representative sector’s stabil-ity is analyzed and the corresponding reinforcementmeasures are presented. DISTRI… 相似文献
18.
抗滑桩在边坡稳定分析中,主要是确定其合理长度和间排距,针对合理长度这个问题,基于有限元法研究了抗滑桩受力和周围土体变形情况,研究发现当桩长到达某一值后,抗滑桩的最大剪力趋于定值、最大弯矩趋于定值,且周边土体位移减小到某值也不再减小;由剪力、弯矩趋于定值和土体位移不再减小得到的抗滑桩长度基本上一致,此值即为采用有限元法得到的抗滑桩长度,并且与实际工程采用的抗滑桩长度对比发现两者长度基本相符. 相似文献
19.
Alan Feingold 《Structural equation modeling》2019,26(3):418-429
Multilevel and latent growth modeling analysis (GMA) is often used to compare independent groups in linear random slopes of outcomes over time, particularly in randomized controlled trials. The unstandardized coefficient for the effect of group on the slope from a linear GMA can be transformed into a model-estimated effect size for the group difference at the end of a study. Because effect sizes vary nonlinearly in quadratic GMA, the effect size at the end of a study using quadratic GMA cannot be derived from a single coefficient, and cannot be used to estimate effect sizes at intermediate time points with backward extrapolation. This article formulates equations and associated input commands in Mplus for time-varying effect sizes for quadratic GMA. Illustrative analyses that produced these time-varying effect sizes were presented, and a Monte Carlo study found that bias in the effect sizes and their confidence intervals was ignorable. 相似文献
20.
The valley shaped Tianziling landfill of Hangzhou in China built in 1991 to dispose of municipal solid waste (MSW) was designed
for a service life of 13 years. The problem of waste landfill slope stability and expansion must be considered from the geotechnical
engineering point of view, for which purpose, it is necessary to understand the geotechnical properties of the MSW in the
landfill, some of whose-physical properties were measured by common geotechnical tests, such as those on unit weight, water
content, organic matter content, specific gravity, coefficient of permeability, compressibility, etc. The mechanical properties
were studied by direct shear test, triaxial compression test, and static and dynamic penetration tests. Some strength parameters
for engineering analysis were obtained.
Project supported by National Natural Science Foundation of China (No. 59508012) 相似文献