甘孜某机场北端地基深厚覆盖层成因及其工程效应

Genesis on Northern Deep Overburden Layer Foundation of an Airport in Ganzi and Its Engineering Effects

四川甘孜州某机场跑道北端存在以砂土为主的深厚覆盖层地基,其成因及工程效应分析是机场稳定性评价的重要部分。该文在详实的现场调查和测绘基础上,通过室内颗粒分析、抗剪、化学分析试验和室外标贯、动力触探、固体体积率、载荷试验、波速测试、抽水试验等,较为系统地研究了场区北端深厚覆盖层地基的工程特征,并结合拟建项目工程特点,对其工程效应进行研究。结果表明:北端覆盖层下部为冰帽初期冰川湖积细砂层,上部为末次冰期含漂砾冰碛层;具有承载力低,地震砂土液化等工程特性。

The deep overburden layer in the north of an airport in Ganzi district of Sichuan province, mainly consists of sand, its genesis and engineering effects analysis are two important parts in the stability evaluation of the airport. On the basis of detailed site investigation, through laboratory particle size analysis, shear test, chemical analyses test, standard penetration test, dynamic penetration, solid volume ratio, load test, wave velocity test, and pumping test, etc. the engineering characteristics of the deep overburden foundation is systemically studied, combined with the engineering characteristics of the proposed projects, the engineering effects are discussed. The results show that： in the lower part of the northern deep overburden layer is made up of gracical lake fine sand layer of early ice cap and the upper is last glacial till, which included some boulder. The deep overburden layer has engineering characteristics with low bearing capacity and soil liquefaction under action of the earthquake.