黄土冲沟中高填方土压力量测及分布规律探讨  

Measurement and distribution of earth pressure of high fill in loess gully

作　　者：朱才辉[1] 李宁[1] 袁继国[1] 

机构地区：[1]西安理工大学岩土工程研究所,陕西西安710048

出　　处：《岩土力学》2015年第3期827-836,共10页Rock and Soil Mechanics

基　　金：国家自然科学基金资助项目(No.51308456);陕西省自然科学基础研究计划项目(No.2013JQ7022)

摘　　要：以吕梁机场黄土高填方试验段为研究对象,采用数值分析、室内试验、原位监测等多种技术手段相结合的方法,分析黄土高填方地基中的土压力量测技术及其空间分布规律,探讨其土压力的计算方法及与理论土压力存在差异的根源。研究结果表明:土压力现场量测时,土压力计埋设槽的高跨比、填筑材料压实度、沟谷坡度等对土压力存在较大的影响,建议现场布设土压力计时采用开孔高跨比λ>0.6比较适宜;根据原位监测结果和三维数值反演分析方法,得到了黄土高填方中部及边界部位的包含填方高度H、填土加权平均重度γ、坡角β等参数的土压力计算公式及其空间分布规律,初步考虑了拱效应对土压力的影响。其研究结果可为类似的黄土冲沟中高填方工程的地下结构设计和地基变形计算提供参考。This paper presents improvement in measurement technology and space distribution of earth pressure of high fill in loess gully. The numerical simulation, laboratory calibration test are used to investigate the factors influencing the measuring resu＞s of earth pressure with earth pressure cell in high fill. It is found that the depth-span ratio of the hole where earth pressure cell is embedded, compaction degree of the fill materials, as well as gully slope, etc., have more significant impacts on testing earth pressure. Therefore the depth-span ratio λ is better recommended to be larger than 0.6. By analyzing in-situ observations at Lüliang airport test section, two earth pressure empirical formulae for middle and marginal regions of the fill respectively are presented, incorporating fill height, weighted average unit weight, slope angle. Using numerical back-analysis, the spatial distribution rules of earth pressure of the high fill are obtained. Comparatively analyses show that the rules from back-analysis are basically in agreement with the ones from empirical formulae. This study can provide references for underground structure design and foundation deformation calculation in similar high fill engineering in loess gully.

关 键 词：黄土冲沟 高填方 土压力分布规律 土压力计标定 原位监测 数值分析 

分 类 号：TU444[建筑科学—岩土工程]