土工离心模型的空间变异性研究  

Spatial Variability of Soil Properties in Geotechnical Centrifuge Models

作　　者：何晔[1] 张璐璐[1] 王建华[1] 张敏[2] 

机构地区：[1]上海交通大学土木工程系,上海200240 [2]深圳大学土木工程系,广东深圳518060

出　　处：《地下空间与工程学报》2011年第5期841-846,共6页Chinese Journal of Underground Space and Engineering

基　　金：国家自然科学基金青年基金项目(50809038)和(41172252);上海市教育基金会"晨光计划"项目(2008CG17);教育部博士点基金资助项目(2008024811128)

摘　　要：土工离心模型的试验结果主要由模型箱内空间平均的土性指标影响。基于随机场的原理,研究了土工离心模型中土性指标的空间变异性。根据实测土密度和孔隙率数据,采用相关函数法计算相关距离,并讨论了模型与原型的空间变异性的相似关系。结果表明,离心模型中土性指标的点变异系数相比原位测试值偏小,相关距离则远小于原位土的相关距离。即使点变异系数和相关距离一致,不同比尺的模型对应原型的空间均值变异系数也不相等。给出了空间均值变异系数云图,可用来调整离心模型以满足原型空间均值变异系数的要求。Performance of a geotechnical centrifuge model is controlled by the spatially averaged soil properties in the model.In this paper,the spatial variability of soil properties in geotechnical centrifuge models is investigated based on the theory of random field.The scale of fluctuation of soil density and porosity of two centrifuge models are estimated using the autocorrelation function method.The similarity of spatial variability between a model and its prototype is also studied.It is found that the point coefficients of variation in centrifuge models are slightly smaller than those in field.The scale of fluctuation in centrifuge models is much smaller than that in field.It is also found that the spatially averaged coefficients of variation are different for the centrifuge models with different size,which are designed to simulate the same prototype.In this paper,a contour plot of the spatially averaged coefficients of variation is provided.One may control the point coefficient of variation and the scale of fluctuation of the soil in a centrifuge model in order to achieve a required spatial averaged coefficient of variation for the corresponding prototype.

关 键 词：离心模型 空间变异性 随机场 相关函数 相关距离 

分 类 号：TU412[建筑科学—岩土工程]