共查询到20条相似文献，搜索用时 515 毫秒
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在大型工程的岩土工程勘察中,如何确定岩石地基的承载力,直接影响到建筑的质量、造价和进度。载荷试验作为模拟建筑物基础受力条件的试验,科学、直观地提供了地基的承载力和变形模量,给设计部门提供了不可或缺的设计依据。然而,岩基载荷试验结果受基岩埋深及孔径的影响尚不清楚。利用ABAQUS有限元分析软件,对深层岩基载荷试验影响因素进行数值模拟分析,得出的结论可为今后岩土工程勘察提供借鉴。 相似文献
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通过对确定软质岩承载力特征值的四种方法即理论计算、抗压强度试验、现场岩基载荷试验和旁压试验的结果的对比与探讨,探讨确定软质岩承载力特征值的合理有效的方法. 相似文献
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本文介绍在常州富都花苑塔楼工程中,用螺旋板载荷试验确定粉土承载力,使该工程的基础方案由桩基降为天然地基,大大节约了工程造价,缩短了施工周期。 相似文献
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岩基载荷试验在设计大直径灌注桩中的应用 总被引：2，自引：0，他引：2
本文分析了目前大直径灌注桩岩基承载力取值方法的现状，并结合岩基载荷试验实例，对ＧＢＪ７－８９规范依据岩石饱和单轴抗压强度确定岩基承载力设计值作了探讨。 相似文献
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利用旁压试验参数确定地基土承载力和模量 总被引：4，自引：0，他引：4
罗晶 《水文地质工程地质》2001,28(3):38-40
本文通过对工程勘察工作中所做的一些旁压试验与载荷试验资料进行对比分析，总结出利用旁压试验参数来确定地基土承载力和模量的方法。 相似文献
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我国是世界上钾肥消耗最大的国家之一,已探明的钾盐资源储量仅占全球资源储量的2%左右,钾盐资源相当贫乏,供需矛盾十分突出。因此,目前在加强钾盐矿普查的同时开展非水溶性钾矿资源的开发利用研究,是解决我国钾肥短缺的有效途径。根据国内对含钾岩石的研究,通过对省内含钾岩石岩石化学资料的收集、整理与分析研究,初步总结了省内含钾岩石的分布特征,将含钾岩石划分为岩浆岩型和沉积岩型两类,并对钾含量较高的岩石的分布进行了概略性研究,初步探讨了找矿前景,提出了可供勘查的矿化潜力较大的地区。 相似文献
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大连市是我国北方严重的缺水地区之一,水资源问题已经成为制约大连市经济可持续发展的一个瓶颈。从大连市水资源环境现状出发,在全面分析大连市水资源承载力系统的基础上,建立了水资源承载力SD模型,模拟了在现状延续型、经济发展型、节水型、协调发展型4种方案下模拟了2005～2025年大连市水资源承载能力的动态变化。结果表明,在建设节水型社会的前提下,水资源循环经济发展是提高大连市水资源承载力的满意方案。 相似文献
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主要介绍了压桩力与单桩竖向极限承载力的关系,以及利用压桩力估算单桩竖向极限承载力的方法。在试桩阶段,位于饱和软土的摩擦桩,压桩力较低,桩的承载力主要来自土体恢复后桩侧的摩阻力。根据静载荷试验检测结果,用单桩竖向极限承载力除以压桩力,引出一个系数,称为压力比,通过分析比较,得出在昆明地区的正常压力比,静压预制管桩在1.3～2之间,静压预制方桩在2.5～5之间。用压桩力乘以压力比,可以估算单桩竖向极限承载力。还简要介绍了挤土效应和超孔隙水压力对桩的承载力的影响。在工程桩施工时,地层中的土体和孔隙水被挤压,形成孔隙水压力,会产生一个向上的浮力,导致已施工的桩上浮,单桩承载力显著降低。 相似文献
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Bearing capacity of rock over mined cavities in Nottingham 总被引：1，自引：0，他引：1
A significant geohazard is created in Nottingham, UK, by hundreds of man-made caves cut in the weak sandstone beneath the city centre. Stability of the caves has been assessed by a single full-scale loading test, by numerical modelling with FLAC and by physical modelling in plaster. For typical caves 4 m wide, bearing capacity of the rock roof rises from 2 MPa where it is 1 m thick to 8 MPa where 3 m thick. Stability decreases over wider caves and where the loading pad edge is over the edge of the cave. Numerical modelling of a very wide cave revealed the failure mechanisms and also showed that an internal support wall increased roof bearing capacity by 50%. Local building regulations that require 3-5 m of rock cover over the sandstone caves appear to be conservative. In stronger rocks, including karstic limestone, a guideline that cover thickness exceeds 70% of the cave width appears to be appropriate. 相似文献
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By using an upper bound limit analysis in conjunction with finite elements and linear programming, the ultimate bearing capacity of two interfering rough strip footings, resting on a cohesionless medium, was computed. Along all the interfaces of the chosen triangular elements, velocity discontinuities were employed. The plastic strains were incorporated using an associated flow rule. For different clear spacing (S) between the two footings, the efficiency factor (ξγ) was determined, where ξγ is defined as the ratio of the failure load for a strip footing of given width in the presence of the other footing to that of a single isolated strip footing having the same width. The value of ξγ at S/B = 0 becomes equal to 2.0, and the maximum ξγ occurs at S/B = Scr/B. For S/B?Scr/B, the ultimate failure load for a footing becomes almost half that of an isolated footing having width (2B + S), and the soil mass below and in between the two footings deforms mainly in the downward direction. In contrast, for S/B>Scr/B, ground heave was noticed along both the sides of the footing. As compared to the available theories, the analysis provides generally lower values of ξγ for S/B>Scr/B. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
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《Geomechanics and Geoengineering》2013,8(4):274-285
By applying the lower bound finite element limit analysis in conjunction with non-linear optimisation, the bearing capacity factors, Nc, Nq and Nγ, due to the components of cohesion, surcharge and unit weight, respectively, have been estimated for a horizontal strip footing placed along a sloping ground surface. The variation of Nc, Nq and Nγ with changes in slope angle (β) for different soil friction angle (φ) have been computed for smooth as well as rough strip footings. The analysis reveals that along a sloping ground surface, in addition to Nγ, the factors Nc and Nq also vary considerably with changes in footing roughness. Compared to the smooth footing, the extent of the plastic zone around the footing becomes greater for the rough footing. The results obtained from the analysis are found to compare well with those previously reported in literature. 相似文献
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Yongfu Xu 《Geotechnical and Geological Engineering》2004,22(4):611-625
It is difficult to determine the bearing capacity of a foundation in unsaturated expansive soil, although this is most important. The bearing capacity of unsaturated expansive soil is related to the drying and wetting environment. Swelling pressure occurs when the soil volume change is constrained as an expansive soil is inundated. The expansive lateral pressure, induced by the swelling pressure is similar to the passive earth pressure. By considering the effect of the expansive lateral pressure in Terzaghi's bearing capacity formula, the bearing capacity of unsaturated expansive soil is derived. Because it is very difficult to measure suction in situ, the bearing capacity is expressed using the expansive lateral pressure offers a feasible approach to calculate the bearing capacity of a foundation in unsaturated expansive soil, when suction is not measured. Plate load tests to measure the bearing capacity in situ were performed for the foundation in natural soil and saturated soil immersed by water. The verification of the bearing capacity formulae presented in this paper is conducted by comparing the predicted results with the results of the plate load tests on unsaturated expansive soils in Handan and Bingxia, China. 相似文献