随机场理论在真空预压软土地基可靠度评价中的应用  

Application of Random Field Theory in the Reliability Assessment of Soft Soils Improved by Vacuum Preloading

作　　者：姜雄 肖熠 周旭东 赵晓东[3] JIANG Xiong;XIAO Yi;ZHOU Xudong;ZHAO Xiaodong(CCCC Third Harbor Consultants Co.Ltd.,Shanghai 200032;Zhejiang Zhongzheng Geotechnical Technology Co.Ltd.,Jinhua 321000;State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology,Xuzhou 221116)

机构地区：[1]中交第三航务工程勘察设计院有限公司,上海200032 [2]浙江中正岩土技术有限公司,浙江金华321000 [3]中国矿业大学深部岩土力学与地下工程国家重点实验室,江苏徐州221116

出　　处：《土工基础》2022年第2期230-234,共5页Soil Engineering and Foundation

摘　　要：真空预压方法在沿海大面积深厚软土场地地基处理中被广泛应用,其具有加快软土排水固结,提高场地地基承载力的双重作用。根据真空预压前后现场原位试验与室内试验数据,采用数理统计的方法对加固前后软土场地土体物理力学指标(含水率、孔隙比)和强度指标(剪切强度、贯入阻力)进行对比分析。针对采用传统计算方法得出的地基可靠度指标偏小、与实际不符的问题,应用随机场理论计算了本区域软土加固后土体指标的相关距离和方差折减函数值,并将其应用地基土可靠度评价中。结果表明:软土经真空预压加固后土体指标仍然符合随机场理论模型,考虑土体指标相关性的地基承载力可靠度指标显著提高,更加符合工程实际,具有重要的应用和推广价值。The vacuum preloading method is widely used in the improvement of large area with deep soft cohesive soils in the coastal plains,which can accelerate the drainage consolidation of the soft clay and improve the shear strength.Based on the in-situ and laboratory tests before and after the vacuum preloading improvement,the physical and mechanical indices(moisture content and void ratio)as well as strength indies(shear strength and penetration resistance)of the soft clay before and after the reinforcement were compared and analyzed by mathematical statistics approach.Based on the difficulties that frequently encountered in the engineering practice of using the conventional analytical approach,such as,small reliability indices,and large deviation from the measure conditions,this paper presents the use of random field approach to obtain the correlation distance and variance reduction function values of soil indices after soft clay improvement in this region.The results are applied to the foundation soil reliability evaluation.The results show that the soil indies of the soft clay after the vacuum preloading improvement are consistent with the values in the random field theory model,and the reliability indices of the soil bearing capacity considering the correlation of soil indies is significantly improved,which is more in line with the engineering practice.

关 键 词：真空预压 随机场 方差折减函数 可靠度评价 

分 类 号：TU472[建筑科学—结构工程]