共查询到20条相似文献，搜索用时 46 毫秒
1.
假定斜坡的滑移面为直线,用极限平衡法推导了倾斜边坡的临界高度和临界坡角,解出了倾斜边坡中安全系数最小的滑动面的位置,确定了边坡中稳定土体的临界角度.结果用解析式表达,为边坡的稳定分析和设计提供了可靠的理论依据. 相似文献
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阐述了时空效应规律在黄土深基坑工程中的运用情况,最后指出,在基坑开挖设计施工时,应充分考虑时空效应,做到分层分段开挖和及时支撑,以减小每步开挖的空间尺寸和开挖、支撑时间,减小基坑变形。 相似文献
3.
严涛 《福建工程学院学报》2012,(4):318-321
从钻进成孔搅拌、提钻杆复喷、张拉锚索3个层面,描述了某基坑支护工程预应力旋喷搅拌锚桩技术,并通过基坑坡顶水平位移和坡顶沉降监测,结果说明,自钻式预应力旋喷搅拌锚桩加冲钻孔灌注围护桩的基坑支护形式,具有基坑开挖施工便捷、基坑边位移小和总体造价低等优点,在周边场地允许的情况下,对于大跨度深基坑支护有很好的适用性和经济性。 相似文献
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5.
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
6.
高层建筑深基坑开挖过程中边坡稳定不容易保证,喷锚支护体系是将锚杆与滑裂面以外土体连成一个整体,再通过外拉系统与深基坑边坡组成一个整体受力体,承受主动土压力,利用土层的锚固力,维持被锚固体(边坡)的稳定,从而使得开挖的基坑获得广阔的空间。 相似文献
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ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｂｕｒｉｅｄｐｉｐｅｌｉｎｅｃａｎｂｅｃｌａｓｓｉｆｉｅｄｉｎｔｏｔｈｒｅｅｄｉｆｆｅｒｅｎｔｔｙｐｅｓ .Ｄｕｅｔｏｔｈｅｄｉｆｆｅｒｅｎｃｅｏｆｔｈｅｒｅｌａｔｉｖｅｓｅｔｔｌｅｍｅｎｔｂｅｔｗｅｅｎｔｈｅｐｉｐｅａｎｄｔｈｅｓｏｉｌｃｌｏｓｅｔｏｉｔｓｔｗｏｓｉｄｅｓ ,ｔｈｅｖｅｒｔｉｃａｌｐｒｅｓｓｕｒｅｏｎｔｈｅｐｉｐｅｖａｒｉｅｓｄｉｆｆｅｒｅｎｔｌｙ .Ｗｈｅｎｔｈｅｆｉｌｌｉｓｈｉｇｈｅｎｏｕｇｈ ,ｔｈｅｖｅｒｔｉｃａｌｐｒｅｓｓｕｒｅｉｓｔｈｅｍｏｓｔ… 相似文献
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宋雷 《兰州石化职业技术学院学报》2020,20(1):10-12
以李家湾大型滑坡治理为工程背景,采用“锚索+抗滑桩”的综合处治方案,利用有限元软件建立滑坡的数值模型并分析滑坡的塑性区、变形机理和特征,与支护后的坡体水平位移和塑性区云图对比,结果表明该方法是分析和治理大型滑坡的最有效途径之一。结果表明:(1)利用有限元软件建立大型滑坡的值模型,通过研究滑坡的塑性区和变形机理,数值模型结果与实际滑坡变形趋势及变形特征基本吻合;(2)未防护的边坡自坡顶至坡脚形成贯通的塑性区(潜在滑面),设置锚索-抗滑桩防护体系的坡体内未形成贯通塑性区,坡体位移趋于稳定,说明防护措施不但合理而且有效,同时为弥补工程经验不足而利用有限元软件模拟支护大型深部位移滑坡,为工程设计设计依据及经验参考;(3)适当的降低设计人员时间和工作量,该方法可为以后大型滑坡动态设计提供依据和经验。 相似文献
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基坑支护设计与施工在江阴地区已经开展多年,由于基坑的影响因素比较多,经常会发生一些事故。通过江阴新百业广场10m深基坑的工程实例分析,在开挖深度比较深、土层地质情况复杂、施工单位又是初次接触深基坑施工的情况下,对工程设计与施工及工程中出现的问题进行原因分析。 相似文献
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This paper presents a deterministic model to predict the pit evolving morphology and crack initiation life of corrosion fatigue. Based on the semi-ellipsoidal pit assumption, the thermodynamic potential including elastic energy, surface energy and electrochemical energy of the cyclically stressed solid with an evolving pit is established, from which specific parameters that control the pit evolution are introduced and their influence on the pit evolution are evaluated. The critical pit size for crack nucleation is obtained from stress intensity factor criterion and the crack nucleation life is evaluated by Faraday’s law. Meanwhile, this paper presents a numerical example to verify the proposed model and investigate the influence of cyclic load on the corrosion fatigue crack nucleation life. The corrosion pit appears approximately as a hemisphere in its early formation, and it gradually transits from semicircle to ellipsoid. The strain energy accelerates the morphology evolution of the pit, while the surface energy decelerates it. The higher the stress amplitude is, the smaller the critical pit size is and the shorter the crack initiation life is. 相似文献
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本文基于国内近些年深基坑工程实践的相关资料,归纳总结了深基坑开挖对周围环境带来的不良效应,以及预防其发生的途径与措施,以期对工程实践具有一定的指导、借鉴作用。 相似文献
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地下水控制是大型深基坑工程中的关键技术。结合某周边不规则的深基坑工程,从基坑周边既有工程环境、施工场地条件、基坑地质和含水层特征等多方面综合考虑,对基坑场地内上层滞水和孔隙承压水分别提出控制设计思路,给出排水管路、深井降水网布置设计方法,以及降水井结构设计图,最后评价地下水控制对深基坑周围环境的影响。对于类似建筑,具有一定的参考价值。 相似文献
13.
地下水控制是大型深基坑工程中的关键技术。结合某周边不规则的深基坑工程，从基坑周边既有工程环境、施工场地条件、基坑地质和含水层特征等多方面综合考虑，对基坑场地内上层滞水和孔隙承压水分别提出控制设计思路，给出排水管路、深井降水网布置设计方法，以及降水井结构设计图，最后评价地下水控制对深基坑周围环境的影响。对于类似建筑，具有一定的参考价值。 相似文献
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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.
This paper introduces a formula for the vertical pressure on a buried pipeline by using a modification of the basic assumptions
of Marston’s theory. The fill’s cohesion is considered. The included angle between the slide surface above the pipeline and
the horizontal surface is assumed to be equal to the fill’s angle of friction. The friction is calculated by multiplying the
active earth pressure on the outer column and the coefficient of the friction on the slide planes It was found that the fill’s
cohesion had important influence on the vertical pressure, whose vertical pressureC
c decreases with increase of the fill depth, a relationship according with that observed in practice. At the end of the paper,
the formula is employed to analyze a practical case.
Project (No. RC9609) supported by Natural Science Foundation of China (NSFC) 相似文献
16.
赵静波 《辽宁科技学院学报》2015,(1):8-9,18
文章采用多井系统理论对湖北潜江高石碑船闸大型基坑深井降水工程进行分析,考虑多井系统相互叠加的结果,对降水总涌水量进行分析,计算井数及每口井的涌水量与实际运行相符,该成果为类似地层超大型深基坑的深井降水工程提供了很好的借鉴作用。 相似文献
17.
介绍了一种新型摩擦实验装置的工作原理、性能和实验结果。该装置设计为滑板转动的传动机构,由转动轴带动滑板转动来调节滑板的倾角,倾角达0°~50°的任意角度。滑板倾角调整分为电动机带动的快速调整和用手动微调2种。该实验装置可以用来测定2种材料之间的静、动摩擦系数,并可以进行一定角度滑板上的物体滑动、翻倒、滚动的演示。实验结果表明,所研制的实验装置具有较好的实验性和可靠性。 相似文献
18.
深基坑开挖支护作为岩土工程的一项基本课题,一直以来是研究的热点和难点.以重庆市沙坪坝区某一工程为研究对象,通过有限元分析软件PLAXIS对深基坑的开挖、支护全过程进行模拟分析,研究支护结构的内力变形情况.发现其水平位移、竖向位移均满足设计要求;发现支护结构弯矩剪应力均发生在其中部位置. 相似文献
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现场监测难以预测基坑和围护结构后期变形规律。采用MIDAS/GTS NX对某地铁车站深基坑开挖及支护全过程进行数值模拟,探寻深基坑开挖引起的地连墙水平位移变化规律,并对比现场监测数据验证数据模拟的可靠性。研究结果表明:随着基坑的开挖,地连墙不同深度下的水平位移变化呈现出内凸的规律,开挖完成时模拟最大水平位移值约为11.6 mm,现场监测最大值约为13.9 mm,最大水平位移位于开挖面附近;改变地连墙厚度及嵌固深度后发现,地连墙厚度及嵌固深度的增大可减小地连墙深层水平位移,但对地连墙顶部水平位移影响较小。研究成果可为深基坑开挖对周边环境影响的分析及类似工程施工方案的优化提供参考。 相似文献
20.
姜铁稳 《毕节师范高等专科学校学报》2014,(6):37-41
因明俗称佛家逻辑,其代表着古印度逻辑的最高成就。因三相理论在整个量论因明学体系中占据着极其重要位置。指出因三相每一相之应有的逻辑含义,并指出对因三相之符号化是一种有益的解读方式,但这种解读因三相之方式似离佛教逻辑之本旨依然有些距离。通过从逻辑和哲学的角度对因三相理论进行分析,以期对因三相有一个更为深刻的认识。 相似文献