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481.
根据多年沉降监测的实际经验,结合国家及行业的有关规范标准,对建筑工程沉降监测的方法、监测点的布设、周期的安排等问题进行了探讨,提出了一些新的见解。 相似文献
482.
Compressibility characteristics of soils 总被引:1,自引:0,他引:1
Compressibility characteristics of soils forms one of the important soil parameters required in design considerations. Compression index, Cc, which is the slope of the linear portion of void ratio, e vs. logaritham of effective pressure p(log p) relationship, is extensively used for settlement determination. The e–log p is most often assumed to be linear at higher pressure range and hence Cc is taken as a constant. Both published experimental results as well as results obtained in this investigation reveal that the e vs. log p could be curved, concave upwards or concave downwards depending upon the soil plasticity characteristics and initial water content. Thus, assuming Cc to be constant may not be valid for many cases. In this paper, an alternate procedure is given to characterise the compressibility of a soil. Experimental results show that the deformation expressed as a percent of thickness of the soil, (strain) vs. effective pressure could be treated as a rectangular hyperbola and the behaviour could be characterised by two parameters, a and b. Characterising the compressibility behaviour with effective pressure by two parameters is better than a single parameter, Cc. 相似文献
483.
Creep and rate of loading effects on geogrid- reinforced sand 总被引:1,自引:0,他引:1
This paper presents the results of studies of creep and rate of loading effects on geogrid-reinforced dune sand. Model plate load tests were conducted on reinforced sand beds under displacement and load controls. Displacement controlled set of plate load tests were carried out in the range 1–0.001 mm/min. Load controlled set of plate load tests were carried out in which the staged pressure was held constant for 6000 min. Results indicate that rate of displacement (strain rate) is very significant for potential improvement of geogrid-reinforced sand. Both stiffness and bearing capacity of geogrid-reinforced sand increases logarithmically with rate of displacement. Geogrid reduces the creep of sand especially in the working pressure range. A simple stiffness degradation and creep relationships were obtained for geogrid-reinforced dune sand. The results of the tests are reported, and the significance of each control variable is assessed. 相似文献
484.
Mariusz Kaczmarek 《国际地质力学数值与分析法杂志》2001,25(8):757-770
In this paper a chemically induced deformation of porous material taking place during advective–dispersive transport of a chemical is considered. Linearized governing equations are derived and analytical solutions of 2 one‐dimensional problems for a homogeneous layer with drained boundaries are developed. Numerical results for a particular clayey material and a chemical migrating through the layer showing distributions of concentration of chemical, changes in porosity of the material and pore fluid pressure, and evolution of settlement of the layer as functions of time are discussed. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
485.
Asaoka法对路堤沉降越级预测初探 总被引:1,自引:0,他引:1
Asaoka法可很好地根据有限次沉降观测结果推算建筑物的最终沉降,但遗憾的是其只能基于本级荷载下沉降观测记录对本级荷载下最终沉降进行预测。本文针对多级填土下的路堤沉降问题,探讨了如何利用该法进行越级预测的思路,给出了该法图解中每级荷载下沉降数据对应的直线在纵坐标轴上截距与路堤高度之间的近似关系。最后,结合工程实例,根据某级荷载下沉降记录对下一级最终沉降作了预测,所得的结果精度还是令人满意的。 相似文献
486.
全过程沉降量预测的Logistic生长模型及适用性研究 总被引:8,自引:0,他引:8
地基的全过程沉降量与时间的关系呈S形曲线,可用Logistic生长模型来描述。目前应用的Logistic生长模型,较少考虑模型的适用范围和预测精度等问题。结合工程实例,比较了模型参数估计的三种方法,研究结果表明,采用非线性回归法估计模型参数,可取得较好的预测效果;根据混沌理论,研究了模型的适用范围和预测性能。Logistic生长模型的动态行为由参数α(瞬时沉降速率)决定,当参数α的取值范围在[0,2]之内,该模型预测的最终沉降量是稳定的。 相似文献
487.
488.
锚杆静压桩施工产生的附加沉降问题初探 总被引:5,自引:3,他引:2
根据锚杆静压桩沉桩时桩周土体的受力模式, 对附加沉降产生的原因进行了分析, 提出了附加沉降的计算公式, 并进行了实例计算与分析。 相似文献
489.
490.