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某厂房由于软土排水固结和地面回填堆载产生地面沉降过大,针对各部位荷载与地质条件的不同情况,分别采用了袖阀管静压注浆和锚杆静压桩托换技术对软土地基进行加固处理,取得了良好效果。介绍了袖阀管静压注浆法和锚杆静压桩托换法的技术特点、加固机理及施工工艺。 相似文献
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高压喷射注浆法可以在软弱下卧土层中直接形成加固桩体对软土地基进行加固。对这种加固方法形成的地基进行了一组模型试验,其中包含了天然地基和加固地基,加固地基中设置了一组3×3的加固桩体,通过对比研究了直接加固软弱下卧土层的地基处理方法对地基工作性状的影响。结果表明:直接加固软弱下卧土层的方法能很好地改善地基的沉降特性,提高地基的承载能力。加固桩体能有效地传递荷载,使加固区软弱土体的压缩量大大减小。随着荷载的增加,加固桩体顶端承担的荷载大体呈线性增加,桩顶轴力表现为角桩最大,边桩次之,中心桩最小。加固桩体上部受负摩阻力作用,下部受正摩阻力作用,桩身最大轴力位于距桩顶25 cm处。加固区的平均桩-土应力比随荷载的增加而减小。 相似文献
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冲填软土地基需要经过地基处理后才能投入工程使用,处理方案一般为浅层地基处理如真空预压处理,但对于大面积大荷载堆载场地,浅层地基处理不足以保证地基稳定性,需进一步做深层地基加固。本文针对广州某造船基地大面积堆载场地,对经真空预压处理后的该类深厚冲填软土地基提出了搅拌桩地基、微型桩地基以及搅拌桩微型桩交错布设地基加固方案,并基于Biot固结理论和有效应力原理,采用有限元分析软件PLAXIS进行数值模拟,对土体选取基于修正剑桥模型的软土模型和Mohr-Coulomb模型,对搅拌桩和微型桩依次选取线弹性模型和弹性模型,计算得到不同加固方案的基础沉降量。基于不同桩型加固机理对计算结果进行进一步分析得出,对此类深厚冲填软土地基,相同桩长的搅拌桩地基加固效果较微型桩效果更明显; 另通过对不同桩长搅拌桩地基加固效果的模拟计算,发现桩长为10m到15m的搅拌桩均能有效加固地基,但随着桩长的增加,加固效果未能显著提高。本研究为冲填软土地基深层加固的设计提供了一定的依据。 相似文献
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在城市建设的基础工程施工中,遇到防空洞时,应根据空洞承载能力和新建筑物基础荷载特点进行分析、判断,选择恰当的加固处理措施。本文介绍了支撑法和贯穿法的特点及适应范围。 相似文献
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常规多次覆盖反射波法地震勘探难以获得100ms(一般相当于80m)以上的有效地震反射信息,形成浅部地层勘探盲区。为有效解决浅层勘探难题,提出了单道自激自收或点组合小排列施工方法。该方法除对震源输出脉冲宽度、频率特性有要求外,还对震源适应性有较高的要求。实例表明:采用小药量震源激发,点组合小排列接收,可有效划分100ms以内的层位;而单道锤击自激自收反射波法,对地下敷设电缆、城市排水沟、地下管道及人防工程的探测效果明显高于常规地震勘探。 相似文献
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The 2004 Indian Ocean tsunami and the 2011 Great Tohoku Japan earthquake and tsunami focused a great deal of the world??s attention on the effect of tsunamis on buildings and infrastructure. When a tsunami impacts structures in a coastal community, the structures are often not strong enough to withstand the forces and may collapse. Therefore, to maximize the survival probability, people evacuate to higher ground or move outside the inundation zone. However, this is not always possible because of short warning times for near-field tsunamis. Thus, sheltering-in-place or ??sheltering-near-place?? using vertical evacuation should be considered as an alternative approach to lateral evacuation from a tsunami inundation zone. This paper presents the method and results of a study to develop and demonstrate a methodology that applied genetic optimization to determine optimal tsunami shelter locations with the goal of reducing evacuation time, thereby maximizing the probability of survival for the population in a coastal community. The City of Cannon Beach, Oregon, USA, was used as an illustrative example. Several cases were investigated ranging from a single shelter to multiple shelters with locations of high elevation already in place near the city. The method can provide decision-support for the determination of locations for tsunami vertical evacuation shelters. The optimum location of the shelter(s), which was found to vary depending on the number of shelters considered, can reduce the evacuation time significantly, thereby reducing the number of fatalities and increasing the safety of a community. 相似文献
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在工程建筑中经常遇到建筑物下方有供水、供气管道或地下防空洞等障碍物,准确测定其位置对其进行处理至关重要。文章结合两个工程实例,对地震影像法和瑞雷波法综合应用在解决这类工程施工中遇到的问题作了简明阐述,说明正确合理的应用该方法具有快速、经济,准确等优点。 相似文献
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滑坡灾害的发生是多因素联合作用的结果,其形成条件、产生原因、变形破坏机制和几何边界条件往往具有复杂性和不确定性,如何选取技术可行、经济合理、安全可靠的防治工程方案,成为能否有效治理滑坡的关键。本文将源自抗震设计中的概念设计方法引入滑坡防治工程设计,提出了滑坡防治工程的概念设计方法。概念设计可结合工程经验和辅助计算方法、试验手段等,在设计中更能体现综合分析、宏观控制。能更好地体现安全可靠与经济适用相结合的设计原则。实践证明该方法是有效而快捷的。 相似文献
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本文以某工程为例,介绍了直达波法测定整板基础砼强度的技术方法;其结果可避免以往回弹法测量结果离散度较大而引起的争议。 相似文献
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You-Liang Chen Rafig Azzam Fu-Bo Zhang 《Geotechnical and Geological Engineering》2006,24(6):1781-1801
Controlling the displacements of foundation pit walls and supporting structures is one of the most effective measures for
ensuring safety of foundation pit construction. Because of this, the accurate displacement computation of foundation pit walls
and supporting structures is paid great attention by geotechnical scientists and engineers. In this paper, the three-dimensional
displacement field of Deping Station foundation pit, which is part of Shanghai Track Traffic Line 6 project, is computed by
means of ANSYS software. Artificial neural networks (ANNs) are a broad category of computer algorithms which have the ability
to learn some target values (desired output) from a set of chosen input data that has been introduced to the network. The
ANNs have very excellent ability in simulating nonlinear and complicated problems. In the current paper, the authors try to
combine FEM method with ANNs so as to improve the computational accuracy. Basing on the computed results, fuzzy control theory
is applied to construction pre-control. The application effect is satisfactory. The research result of current paper is very
helpful for geotechnical construction and the development of geotechnical theory. 相似文献