大厚度自重湿陷性黄土地基处理深度和剩余湿陷量问题的合理控制  

Foundation treatment depth and reasonable control on remnant collapse in area of dead weight collapse loess with great thickness

作　　者：张世径[1] 黄雪峰[1,2] 朱彦鹏[1] 杨校辉[1] 姚志华[2] 

机构地区：[1]兰州理工大学土木工程学院,兰州730050 [2]解放军后勤工程学院建筑工程系,重庆401311

出　　处：《岩土力学》2013年第S2期344-350,共7页Rock and Soil Mechanics

基　　金：国家电网公司科学技术项目(No.SGKJJSKF[2008]656)

摘　　要：为研究大厚度自重湿陷性黄土地区地基处理深度与剩余湿陷量的合理控制关键技术难题,对采用不同处理深度的挤密地基进行了大面积深层浸水载荷试验。试验结果表明:对采用挤密地基处理在6~12 m深度以下进行深层浸水后均发生不同程度的地基湿陷下沉,而地基处理在15 m深度时(剩余湿陷量远大于200 mm)地基整体实际下沉量相对较小,说明现行的《湿陷性黄土地区建筑规范》对乙、丙类建筑地基关于最小处理深度的规定过于严格,不符合现有的经济技术水平,建议在采取一定措施的情况下将12~15 m作为乙、丙类建筑在大厚度自重湿陷性黄土地区地基处理的合理深度。并针对现行规范中对乙、丙类建筑剩余湿陷量控制的不合理之处,提出了'剩余湿陷量折减系数'这个概念,并提出了该折减系数的建议值,可为同类工程建设和规范修订提供一定的参考。In order to research the reasonable controlling critical technical problem of ground treatment and remnant collapse in the area of dead weight collapse loess with great thickness, a large area and deep level immersion load test was made for pile ground by using different treatment depths. The test results indicate that the foundation treated by the pile ground would have the occurrence of different degrees of foundation collapse settlement after deep immersion in the range of 6-12 m. The remnant collapse of foundation treatment in the depth of 15 m is more than 200 mm;and the foundation’s whole subsidence is relatively small. This phenomenon indicates that the current regulation, Code for Building Construction in Collapsible Loess Regions, is too strict about the minimum depth of treatment for class B and class C building foundations;and it dose not agree with the current standards of economy and technology. It is suggested that the 12-15 m could regard as the foundation treatment rational depth for class B and class C buildings in the area of dead weight collapse loess with great thickness. In light of unreasonable regulations about the remnant collapse of class B and class C buildings in current code, this article puts forward the concept of “remnant collapse reduction factor” and its recommended value, so as to give a reference for the same kind of construction projects and code revision.

关 键 词：大厚度自重湿陷性黄土 挤密地基 深层浸水 剩余湿陷量 合理处理深度 剩余湿陷量折减系数 

分 类 号：TU444[建筑科学—岩土工程]