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1.
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
2.
Using geotextile bag dehydrated soil to construct dikes for land reclamation to substitute conventional straw bags is an urgent need in Tianjin New Harbor, China. This paper introduces the method to build a dike for hydraulic filling. The soil for filling the geotextile bags was tested in wave trench ; the stress developed during construction was calculated by establishing a numerical model and compared with the tensile strength of the geotextile; the stability and settlement of the dike were estimated by performing centrifuge tests. Through this study, the following information was obtained: 1 ) The cohesionless silt with plasticity index less than 10 is suitable for filling the geotextile bags. The geotextile bag dehydrated soil consolidated very quickly even under the action of wave force. 2) A numerical model was devised to find the limit injection height and to calculate the tensile stress developed in the geotextile bags when they were piled up to form the dike. The calculated stress was compared with the strength of the geotextile, showing that the design is reasonably safe. 3) Centrifuge test results show that the designed dike will be stable and the settlement of dike will be less than the design requirement. 相似文献
3.
研究了采用离心模型试验来研究波浪与土相互作用的方法,并针对渤海某油田的波浪及土质条件进行了试验研究.结果表明,在最大波高作用下,软粘土层的上部发生了软化,但这种影响随着深度的增加而逐渐减小;在波浪荷载的作用下,软粘土层下的粉砂层没有液化迹象. 相似文献
4.
Ultrasonic wave testing was applied to investigate the quality and weathering status of rock specimens obtained in two borings
situated in the Xishan Buddha rock slope in Taiyuan, China. This paper pays special attention to the distribution of bulk
density, dynamic parameters and static parameters of rock specimens as well as the relationship between static and dynamic
parameters. The results illustrate that the distribution of both parameters is identical along the depth of two drilled holes
in the rock slope. When the hole depth increases, the density of rock mass, saturated compression strength and static elastic
modulus, dynamic elastic modulus and wave velocity also show increase tendency. The weathering degree in the rock mass ranging
from the surface of cliff to the depth of 2.5 m is the highest while the rock mass is unsalted and more rigid when the depth
is larger than 3.0 m. The relationship between dynamic elastic modulus, sonic wave velocity and horizontal depth indicates
that dynamic elastic modulus is more sensitive than sonic wave velocity. Conversely, by comparing quantity relationship between
static elastic modulus and sonic wave velocity, it is found that the composition of rock has a great influence on the relationship
between static and dynamic parameters, that is, inequality of rock composition will lead to dispersion and abnormality of
the distribution of static and dynamic parameters. 相似文献
5.
分析了不同含水量下黏聚力和内摩擦角的变化规律．通过选取不同含水量下的黏聚力和内摩擦角参数值建立数值模拟模型,模拟厚土坡损伤破坏的过程,以探求降雨入渗作用下厚土边坡的破坏机理。结果表明,含水率对边坡变形有较大影响．含水率对厚土坡变形的影响规律与其对黏聚力的影响规律相反,随含水率逐渐增大,厚土坡向临空面的变形呈先减小后增大的特征。 相似文献
6.
在考虑坝水耦合振动影响下,对拱坝边坡在地震作用下承受的动水压力进行了理论分析和数值计算。对正常蓄水位时、枯水位时边坡地震响应进行了分析。包括边坡的损伤演化、应力、位移的分析。在水坝地震动力分析中,应当将边坡、库水和地基三者作为一个综合的振动系统进行动力分析,考虑它们之间的相互作用,为类似库区边坡稳定性评价和边坡加固提供理论依据。 相似文献
7.
The response of dynamic wave pressures on structures would be more complicated and bring about new phenomena under the dynamic interaction between soil asnd structure.In order to better understand the response characteristics on deeply embedded large cylindrical structures under random waves,and accordingly to offer valuable findings for engineering ,the authors designed wave flume experiments to investigate comparatively dynamic wave pressures on a single and on continuous cylinders with two different cembedment depths in response to two wave spectra ,The time histories of the water surface elevation and the corresponding dynamic wave pressures exerted on the cylinder were analyzed in the frequency domain,By calculating the transfer function and spectral density for dynamic wave pressures along the height and around the circumference of the cylinder,experimental results of the single cylinder were compared with the theoretical results based on the linear diffraction theory ,and detailed comparisons were also carried out between the single and continuous cylinders ,Some new findings and the corresponding analysis are reported in present paoer,The investigation on continuous cylinders will be used in particular for reference in engineering applications becaus information is scarce on studying such kind of problem both analytically and experimentally. 相似文献
8.
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
9.
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
10.
陈友根 《福建工程学院学报》2002,(2)
针对一露天边坡第四系土层厚 ,透水性强 ,河流距边坡近 (仅 5 0米 ) ,形成直接补给 ,临近边坡的铁路专用线位于边坡上方 ,边坡安全稳定要求高 ,研究采取地下止水帷幕和疏干排水等综合治理技术。 相似文献
11.
盐渍土水分下渗能力及水盐动态运移试验 总被引：1，自引：0，他引：1
为探究盐渍化土壤水分下渗规律、水分下渗能力及水盐动态运移过程,设计了土壤剖面分层定水头供水及土壤剖面变水头供水下渗实验。测定不同层位土壤水分下渗率、含水率、孔隙水溶液电导率及土壤体电导率等参数,进行入渗条件下水盐动态运移规律分析。试验结果表明:盐渍化土水分下渗规律可由积水入渗Kostiakov模型进行刻画;浅层0~40 cm土壤相对于深层40~60 cm土壤具有较强的拦截和贮存入渗水分能力;盐渍化土壤盐分变动带位于浅层0~40 cm,且20~40 cm深度的土壤盐分波动幅度较大,深层40~60 cm土壤孔隙水溶液盐分向下运移的通量与土壤体盐分对其的补充量达到动态平衡,水分下渗过程中深层土壤孔隙水盐分含量相对平稳。实验结果为盐渍土的防治提供参考。 相似文献
12.
微地形条件下地表填洼量计算方法研究 总被引：1，自引：0，他引：1
地表填洼量是地表相对低洼处蓄存的水量,与地表径流与土壤侵蚀过程有直接关系。本文通过模拟黄土坡耕地普遍采用的人工锄耕和人工掏挖耕作措施下地表特征,探讨了地表填洼量的计算方法。结果表明：地表洼地空间分布较随机,人工掏挖措施下呈斑点大而少,人工锄耕下斑点小而多的特征;地表填洼量与坡面洼地面积呈显著正变函数关系,可以作为研究区坡耕地上人工锄耕和人工掏挖措施下地表填洼量的计算公式。 相似文献
13.
In-situ vane shear test is frequently performed to determine shear strength for slope stability analysis in Tianjin New Harbor. However,the soil shear strength varies with the shear plane orientation. A possible means to reduce the effect of directional dependency of shear strength is to convert the in-situ vane shear strength into undrained shear strength parameters. A method of converting in-situ vane shear strength into undrained shear strength parameters is presented. The shear strength parameters determined for all of the in-situ vane shear strengths are subjected to statistical regression analysis to take into consideration the possible effect of non-homogeneity in the soft clay deposit. Using the regressed shear strength parameters, slope stability analyses are performed for five existing soil slopes. The results of stability analyses indicate that the safety factors obtained from the converted parameters reflect the state of the slopes analyzed much better than those obtained from in-situ vane shear strength and laboratory consolidated-undrained and unconsolidated-undrained strength parameters. It is concluded that the presented methsod of determining undrained shear strength parameters for in-situ vane shear strength is effective. 相似文献
14.
Using the self-developed visualization test apparatus, centrifuge model tests at 20g were carried out to research the macro and microscopic formation mechanism of coarse sand debris flows. The formation mode and soil-water interaction mechanism of the debris flows were analyzed from both macroscopic and microscopic points of view respectively using high digital imaging equipment and micro-structure analysis software Geodip. The test results indicate that the forming process of debris flow mainly consists of three stages, namely the infiltration and softening stage, the overall slide stage, and debris flow stage. The essence of simulated coarse sand slope forming debris flow is that local fluidization cause slope to wholly slide. The movement of small particles forms a transient stagnant layer with increasing saturation, causing soil shear strength lost and local fluidization. When the driving force of the saturated soil exceeds the resisting force, debris flow happens on the coarse sand slope immediately. 相似文献
15.
某拟建场地位于山脊山谷地带切削填平的土质边坡上,该边坡总体高度36.4 m,为超高填土边坡,按照规范要求,该类边坡应进行特殊设计。考虑到边坡的自重固结尚未完成,承载能力较低,在工程地质勘查和室内试验获得的土体物理力学性质的基础上,采用FLAC3D对该边坡的场地适宜性进行了数值模拟分析。结果表明：该边坡在自重固结作用下或施加拟建建筑荷载后,产生较大的竖向沉降和水平位移,直接作为建筑场地将存在较大的隐患,需要结合桩锚联合支护等方案进一步研究探讨。 相似文献
16.
刘国栋 《商洛师范专科学校学报》2013,(4):63-66
对西安市某均质土坝,库水位在最高水位的工况下,用有限元分析软件Geo—slope计算分析了背水面不同高度的透水边界对渗流场和背水面边坡安全系数的计算结果的影响。结果发现,背水面透水边界在合理的高度以下上升时总流量、出溢流量、出溢口处水力坡降、背水面边坡安全系数增大;背水面透水边界在合理的高度以上升高时这四个代表值减小。说明了合理的背水面透水边界为各个流场代表值和边坡安全系数的极值点。 相似文献
17.
研究目的：创新要点：为多塔斜拉桥在一致激励和非一致激励下地震响应的研究提供地震模拟振动台全桥试验方法,并有助于加强多塔斜拉桥抗震性能和抗震设计的认识。1．建立了地震模拟振动台多台阵试验方法,并首次将其应用于多塔斜拉桥全桥比例缩尺模型的地震响应分析之中;2．通过地震模拟振动台试验,揭示了多塔斜拉桥在多点一致激励和多点非一致激励的地震响应特性并提出了多塔斜拉桥在强震下的破坏模式。研究方法：1．基于动力相似理论,设计与制作了多塔斜拉桥的全桥比例缩尺模型（图2）;2．利用地震模拟振动台多台阵试验,根据在不同地震波作用下和考虑行波效应后多塔斜拉桥模型的主梁和主塔响应,分析了多塔斜拉桥在多点一致激励和多点非一致激励的地震响应特性（图5～图8）;3．根据在地震波不同强度作用下多塔斜拉桥模型的主梁和主塔响虚,分析了多塔斜拉桥在强震下的破坏模式和地震响应（图9）。重要结论：1．江心波作用下该多塔斜拉桥的地震响应大于其他三种地震波;2．多塔斜拉桥在抗震设计时需要考虑行波效应的影响;3．在El-Centro波的加速度峰值高达4．0m／s^2时,多塔斜拉桥模型出现了支座破坏。 相似文献
18.
以紫金山金铜矿开采为工程背景,根据矿山规划设计,露采至+100 m水平后进行井工开采。为了研究井工开采对露天边坡的影响,采用FLAC3D建立数值模型,研究采区位于边坡体不同空间位置对边坡稳定性产生的不同作用机制,分析露天边坡和采空区围岩位移演化规律、应力分布规律。数值模拟结果表明:当井采区位于边坡坡脚区时,井工开采直接破坏了坡脚区边坡岩体,坡面整体向坡脚处滑移,最大水平位移达到2.21 m,最大竖向位移达到1.67 m;当井采区位于坡中区开采时,其开采破坏了坡中边坡岩体,可能导致上部坡体失稳破坏;当井采区位于坡外区时,由于采区上部岩层沉陷导致边坡整体坡角减小,从而有利于边坡整体稳定性。对比3种开采位置,采区位于坡脚时对边坡稳定性最不利,采区处于坡外时采动效应对边坡稳定性的影响最低。 相似文献
19.
INTRODUCTIONTheTianzilingwastelandfillbuiltin 1991toproperlydisposeofmunicipalsolidwaste(MSW)hasadesignedservicelifeof13years.Itwasfilledstagebystageatthebeginningoftheelevationof 50 .5m .Bynow ,thelandfillhasreachedthelevelof 10 2 .5m ,whichex ceedst… 相似文献
20.
Numerical simulation on floating behavior of buoyancy tank foundation of anemometer tower 总被引：1，自引：0，他引：1
The intact stability and damage stability of a model of an anemometer tower with buoyancy tank foundation are computed by the finite element software MOSES in this paper. The natural period of the anemometer tower is discussed through frequency domain analysis. The influence of a single factor, such as towing point position, wave height, wave direction and wave period, on towing stability is discussed through time domain analysis. At the same time, the towing stability under the condition of various combinations of many factors is analyzed based on the meas- ured data of the target area. Computer simulation results show that the intact stability is preferable and the damage stability is sufficient under the condition of plenty of subdivisions. Within the scope of the buoyancy tank foundation, the higher the towing point position is, the better the stability is. Wave height has a great impact on the motion amplitude of buoyancy tank foundation, but the effect on the acceleration is not obvious; wave period has a great impact on the acceleration, while the effect on the motion amplitude is not obvious; following-waves towing is more conducive to safety than atry. 相似文献