北京东部地区非饱和粉砂层原位直剪试验成果分析  

Analysis on In-situ Direct Shear Test Results of Unsaturated Silty Sand in the Eastern Part of Beijing

作　　者：张向营 周玉凤[1,2] 杨浩军 冯建洋 程秋实 Zhang Xiangying;Zhou Yufeng;Yang Haojun;Feng Jianyang;Cheng Qiushi(Beijing Urban Construction Exploration and Surveying Design Research Institute Limited Liability Company,Beijing 100101,China;Beijing Key Laboratory of Geotechnical Engineering for Deep Excavation of Urban Rail Transit,Beijing 100101,China)

机构地区：[1]北京城建勘测设计研究院有限责任公司,北京100101 [2]城市轨道交通深基坑岩土工程北京市重点实验室,北京100101

出　　处：《岩土工程技术》2024年第1期106-109,共4页Geotechnical Engineering Technique

摘　　要：对北京东部地区典型非饱和粉砂层进行原位直接剪切试验,采用最小二乘法拟合得到黏聚力和内摩擦角指标,其内摩擦角指标相比于传统地区经验值和室内直接快剪试验值分别提高了11.11%~24.4%、3.01%~17.40%;室内直接快剪试验测得粉砂层的黏聚力为4.8~7.5 kPa,而原位直剪试验测得该值最高达9.5 kPa。研究成果为该地区非饱和砂土层的剪切指标参数优化提供了试验支撑,节约了基坑支护造价,为实现工程建设全过程绿色建造提供了可能。For the typical unsaturated silty sand layer in the eastern part of Beijing,in-situ direct shear tests were conducted,and the cohesion and internal friction angle were obtained by the least squares method.The internal friction angle values are increased by 11.11%~24.4%compared to traditional regional empirical values,and by 3.01%~17.4%compared to the values from the indoor direct shear test.The cohesive force of the silty sand layer measured by the indoor direct shear test is 4.8~7.5 kPa,while the value measured by the in-situ direct shear test is up to 9.5 kPa.The research results provide experimental support for the optimization of the shear index parameters of the unsaturated sand layer in this area,save the cost of foundation pit support,and provide the possibility for realizing green construction in the whole process of engineering construction.

关 键 词：非饱和砂土 原位直剪试验 剪切强度指标 

分 类 号：TU413[建筑科学—岩土工程]