摘要
基于某机场工程场区工程地质和水文地质特征,对黄土的湿陷性进行评价,采用室内土工试验、标准贯入试验和现场直剪试验,对湿陷性黄土地基强夯处理效果进行分析评价,采用直剪试验结果对高填方边坡稳定安全系数进行复核计算,结果表明:①通过强夯试验性施工,确定最佳夯击数为6击,整体夯沉量约40 cm;②强夯后黄土密实度明显提高,标贯击数沿着深度几乎线性增加;③场区黄土层为低液限黄土状粉土,稍湿,密实,压缩性低;④强夯消除场区内黄土的湿陷性;⑤强夯后黄土内摩擦角变化较小,粘聚力变化较大,通过直剪试验抗剪强度指标复核边坡稳定性,稳定安全系数满足规范要求。研究成果对西北地区机场工程湿陷性黄土地基的设计处理具有一定的参考意义。
The collapsibility of loess soil fill materials was evaluated based on the site-specific engineering geology and hydrogeological characteristics of an airport project.The effect of dynamic compaction on the collapsible loess fills was evaluated throughout the laboratory soil tests,field standard penetration test and in-situ direct shear test.The results from the in-situ direct shear tests were used to evaluate the stability safety of the slope of a high fill embankment.The following conclusions can be summarized:(1)The optimum number of blows of dynamic compaction was 6 and the accumulated settlement was about 40cm through trial test zone;(2)The density if the loess was apparently improved after the dynamic compaction.The blow counts of standard penetration test increased almost linearly along the depth.(3)The loess soil layer in the field is characterized by the low liquid limit loess-like silt,slightly wet,dense,low compressibility.(4)After the ground improvement by dynamic compaction,the collapsibility of loess in the field was eliminated.(5)After the dynamic compaction,the internal friction angle of loess samples become less variable with a significantly variable cohesion values from the in-situ direct shear test result.The in-situ tested shear strength values could be used for the slope stability evaluation of the high fill embankment.It is concluded that stability of the loess fill embankment met the design requirement.
作者
李海鹏
朱恒元
LI Haipeng;ZHU Hengyuan(China Airport Planning&Design Institute Co.,Ltd.,Beijing 100101;Urumqi Airport Development Construction Investment Group Co.,Ltd.,Urumqi 830000)
出处
《土工基础》
2019年第6期634-638,共5页
Soil Engineering and Foundation
关键词
湿陷性黄土
强夯
直剪试验
标贯
土工试验
边坡稳定性
Collapsible Loess
Dynamic Compaction
Direct Shear Tests
Standard Penetration Tests
Laboratory Tests of Soils
Slope Stability
作者简介
李海鹏(1989-),男,硕士,工程师,研究方向为地基处理与边坡支护。
