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高压喷射注浆处理地基不均匀沉降的实践 总被引:1,自引:0,他引:1
左文贵 《水文地质工程地质》1998,25(4):57-58
高压喷射注浆处理地基不均匀沉降的实践1工程概况珠江市某厂程控电话楼建成于1992年。建筑物西北端为主楼,高5层17.5m,场地原为小山包的东南坡前缘,平整时即见第三系红色泥质粉砂岩残积层或强风化层;东南端为群楼,高3层10.80m,场地原为一小水塘。... 相似文献
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某地基不均匀沉降的三维分析 总被引:5,自引:2,他引:3
某地基处理原拟采用CFG复合地基。但由于地层情况复杂 ,施工难度大 ,决定采用CFG桩和人工挖孔桩进行地基处理 ,但是这种处理方案可能会引发地基不均匀沉降从而对上部结构产生不良影响 ,因此合理的的选取人工挖孔桩桩间距非常重要。通过对四种桩间距情形下地基的三维沉降分析 ,选取了合理的人工挖孔桩桩间距 ,解决了这一工程难题. 相似文献
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张栋材 《水文地质工程地质》2001,28(5):69-72
某油罐因地基发生不均匀沉降而倾斜,本文通过对油罐发生不均匀沉降的原因分析,提出了倾斜油罐纠偏设计及地基处理方案;叙述了地基处理及纠偏施工方法.施工处理后经过半年的使用观察,效果良好. 相似文献
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桂林市软土工程地质特征及地基处理的探讨 总被引:1,自引:0,他引:1
桂林市软土分布广、厚度变化大,在下状基岩岩溶化强度较高时,上覆软土发育,反之则不发育。其软土工程地质特征具有:高含水性、高压缩性、低强度、高孔隙比、低渗透性、高蠕变性、不均匀性、高灵敏度等8种特性,因此决定了其强度低、压缩性高;作为地基时,其承载力低、沉降量大、易于产生不均匀沉降。软土地基处理的实质主要是增大其密度;而在作桩基时,无论是桩的承载力,或是桩的变形均应密切重视。另外,本文还对软土与土洞、塌陷间关系作了初步探讨. 相似文献
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在软土地基上修建道路,变形是控制道路质量和正常使用的主要因素。天津东疆港道路建立在经真空预压加固后的吹填土地基上,道路使用3 a后产生了严重的"波浪型"不均匀沉降,严重影响了车辆的行驶及人的生命安全。通过分析软土路基产生波浪变形的机制,提出了道路在建成后产生初始波浪变形,在车辆荷载作用下加剧了这种不均匀沉降的理念;建立了软土路基在波浪变形初值缺陷条件下的力学模型,通过力学分析与计算得出,在初始波浪变形条件下路基波谷受到比波峰大的车辆荷载;路基波峰与波谷处车辆动载大小的不同是加剧地基不均匀沉降变形的原因。提出利用土工格栅的加筋作用可减小不均匀沉降,通过有限元方法分析了该措施的加固效果。 相似文献
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本文主要介绍:在近期海相沉积的软粘土层上,采用砂垫和砂井结合(即混合砂地基),上部结构施工前不进行堆载预压的办法,修建多层砖房的设计和施工。1979年夏动工,1981年冬竣工交付使用,近三年来使用情况良好,未发现异常变形,达到预期效果,施工简便,经济效果显著,是砂井排水固结处理软粘土地基,应用在房屋建筑上成功的一例。 相似文献
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This paper deals with the relation between loam behaviour and its differential settlements. Experimental results obtained from the foundation soil of a phosphtic fertilizer plant show that factors influencing differential settlements are: (1) Comparatively large compressibility of foundation soil; (2) Anisotropic strength of foundation soil; (3) Overloading and repeat loading effects; (4) Fluctuation of underground water table; (5) Rheologic property of foundation soil. 相似文献
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One of the effective utilization strategies for fly ash and waste sludge is to use it as a fill material to raise low lying areas. Bearing capacity and settlement are the required input for the design of foundations on such fills. To determine the bearing capacity, plate load tests were carried out on the compacted beds of fly ash, fly ash-waste sludge and fly ash-waste sludge–cement. The tests were conducted by keeping 90, 95 and 100 % relative compaction, fresh and fresh submerged conditions, aged (28 days) and aged (28 days) submerged conditions as variables of the tests. The load-settlement curves were plotted for fly ash and mix blends. The minimum load was obtained for fly ash under submerged condition, further the test results show that the fly ash becomes flowable on submergence. On the other hand when the fly ash was mixed with waste sludge and cement, the load carrying capacity was found to improve to a greater extent. Test beds prepared with fly ash–cement-waste sludge under as compacted condition (fresh) show very high load carrying capacity (1600–2180 kN/m2). An analytical method has also been validated for fly ash–cement-waste sludge mix which was developed to estimate the settlement of footing resting on fly ash taking into account the pre-consolidation stresses. The non linearity of load-settlement behavior was appropriately modeled, on the basis of available plate load test data incorporated in the method. The method requires as input, the pre-consolidation stress and Young’s modulus of compacted mix of fly ash-waste sludge–cement. A comparison of load-settlement values observed in plate load tests and predicted values for the mix 47 %FA + 45 %S + 8 %C, using the proposed method shows good agreement. Hence, this relationship may also be useful to the field engineers to check the reported load-settlement values for such types of mixes in the field. 相似文献
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通过对某建筑物结构构件的裂缝以及不均匀沉降的观测,分析了产生工程质量事故的原因,确认是由于地下水位的变化,引起地下室不均匀隆起与沉降所致。介绍该工程采用的静压锚杆抗浮、包钢灌浆、碳纤维加固进行处理,结果表明综合加固补强措施达到了满意的效果。 相似文献
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在软基路段上建造预制梁场,合理的布设预制梁台座能有效地减小软基差异沉降。采用有限元软件Midas/GTS建立三维计算模型,分析不同预制梁台座布设形式对软基差异沉降的影响。结果表明:当梁台座按横向排布时,梁场中部的梁台座总沉降量与每2 m长度上的最大差异沉降量均比外侧要大,且每2 m长度上最大差异沉降量较纵向排布大,建议优先纵向布设预制梁台座;当台座采用扩大基础时,台座总体沉降量比浅基础明显减小,最大沉降量由11.6 mm降低至8.5 mm,台座的2 m长度上的不均匀沉降量由0.41 mm降低至0.12 mm,建议优先选用扩大基础台座。 相似文献
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Please refer to the attachment(s) for more details. 相似文献
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Geotechnical and Geological Engineering - In the embankment widening project, the new embankment will produce large deformation due to the low degree of consolidation, which will affect the... 相似文献
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The effect of microfabric on the mechanical behaviour of clays has been explored previously based on the response of dispersed and flocculated microfabrics only. However, the natural clays often have the geometric arrangement of particles between these two extreme cases which can be termed as intermediate microfabric. This paper explores the formation of intermediate microfabric of kaolin clay and its impact on soil’s consolidation behaviour by performing self-weight consolidation, slurry consolidation and 1-D consolidation tests. The effect of calgon content (dispersing agent) on geometric arrangement of the particles has been evaluated through cluster size distribution by performing double hydrometer tests. Then these clay slurries have been used to perform the AFM (Atomic Force Microscopy) test to obtain the variation in average angle of particle orientation with respect to the calgon content present in the slurry. AFM technique provides 3D image of the clay sample and 2D image with Z-information with the potential of measuring intermediate microfabric of clayey soil quantitatively including dispersed and flocculated microfabrics. Other traditional techniques such as SEM, TEM & XRD are limited to only qualitative analysis of soil’s microfabric, thus, having no capability to measure intermediate microfabric of clay. A methodology of preparing bulk specimens of clay with intermediate microfabric has been developed using slurry consolidation technique; and then these specimens have been consolidated under 1-D loading to evaluate the effect of intermediate microfabric on compressibility and permeability of clay. In this study, all the experiments reports that the dispersed type geometric arrangement increases with the increase in calgon content in soil up to 2 % and then the reverse behaviour is observed at 3 %; which may depend on the required amount of sodium cations to neutralize the negatively charged faces of the clay platelets present in the slurry. 相似文献
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选取三氯乙烯(TCE)、顺-1,2-二氯乙烯(cis-1,2-DCE)、1,1,1-三氯乙烷(1,1,1-TCA)、1,2-二氯乙烷(1,2-DCA)4种常见的有机氯代烃,通过批次实验研究其在壤土中的吸附和解吸特性。结果表明:4种有机氯代烃在壤土中的吸附平衡时间约为3 d;在本文研究的整个浓度范围内,4种有机氯代烃的吸附等温线基本呈线性趋势,但更符合Freundlich模型。对于有机氯乙烯而言,TCE在壤土中的吸附特性较为显著,线性分配系数Kd为0.624 L/kg,其次是cis-DCE,Kd为0.238 L/kg;对于有机氯乙烷而言,1,1,1-TCA在壤土中的吸附特性较为显著,Kd为0.520 L/kg,其次是1,2-DCA,Kd为0.353 L/kg。这进一步表明4种有机氯代烃化合物在壤土中的吸附特性与化合物本身的疏水性有关。通过Abdul、Dobbs、Rao和Cong经验公式估算lgKoc值发现,Abdul估算所得lgKoc比实测值偏小,Cong估算lgKoc比实测值偏大,Dobbs和Rao与实测值更为接近;说明 Dobbs和Rao经验公式更适用于预测有机氯代烃化合物在壤土的吸附特性。另外,研究发现有机氯代烃的解吸过程具有明显的滞后性,吸附特性较强的物质,其解吸较为缓慢。 相似文献