基于SPT-APD-DDA的砂土液化评价方法研究  

Evaluation method of sand liquefactionbased on SPT-APD-DDA

作　　者：郝少雷 张兵[1] 徐世光[1,2] 李岳峰 陈梦瑞 邓立雄 郭薇 HAO Shaolei;ZHANG Bing;XU Shiguang;LI Yuefeng;CHEN Mengrui;DENG Lixiong;GUO Wei(Faculty of Land Resource Engineering,Kunming University of Science and Technology,Kunming 650093,Yunnan,China;Yunnan Geology and Mining Engineering Survey Group Corporation,Kunming 650000,Yunnan,China)

机构地区：[1]昆明理工大学国土资源工程学院,云南昆明650093 [2]云南地矿工程勘察集团公司,云南昆明650000

出　　处：《地震工程学报》2023年第4期877-886,共10页China Earthquake Engineering Journal

基　　金：国家自然科学基金(40961001)。

摘　　要：传统的规范法在建立经验判别准则过程中存在大量不确定性因素,工程中亟需针对复杂场地液化判别方法的综合性研究。通过对上海市包头路段沉管抢修项目49组砂土土样的研究,在标准贯入试验法(SPT)定性评价的基础上采用提出的绝对差值百分比法(APD),划分出35组判别结果精确及14组存在判别误差的土样。借鉴判别分析理论思想,将平均粒径D50、不均匀系数Cu、比贯入阻力Ps、标准贯入点深度ds、地下水埋深dw和标准贯入锤击数N63.5等物理力学参数加入液化评价,利用精确土样建立适宜研究区工程地质特性的距离判别分析模型(DDA),对14组存在判别误差或失误的土层进行定量评价。研究结果表明:建立的砂土液化综合评价体系对研究区具有较强的针对性与适应性,从多角度全面、客观地评价了研究区砂土液化情况。最终通过合理的抗液化沉陷措施,保障了后续工程的稳步进行,为类似地质条件场区的砂土液化稳定性评价提供参考和借鉴。Many uncertain factors exist when establishing the empirical criteria with traditional methods.Thus,comprehensive research on the liquefaction criteria for complex sites needs to be conducted.In this paper,49 groups of sand samples from the emergency repair project of immersed pipe of the Baotou section in Shanghai were studied.This paper first adopted the standard penetration test method to qualitatively evaluate the sandy silt soil within 20 m of the research area.With the use of the absolute difference percentage method proposed in this paper,35 groups of soil samples with accurate discriminant results and 14 groups with discriminant errors were divided.Then,referring to the theoretical thought of discriminant analysis,the physical and mechanical parameters such as average particle size D 50,uneven coefficient C u,specific penetration resistance P s,standard penetration point depth d s,groundwater depth d w,and standard penetration blow count N 63.5 were added to the liquefaction evaluation.Finally,with the use of the soil samples with accurate discriminant results,a distance discriminant analysis model suitable for the engineering geological characteristics of the research area was established to quantitatively evaluate the soil layers of samples with discriminant errors.Research results show that the established comprehensive evaluation system for sand liquefaction comprehensively and objectively evaluates the sand liquefaction in the study area from multiple perspectives.Through reasonable anti-liquefaction and subsidence measures,the steady progress of subsequent projects is guaranteed,and a reference for the stability evaluation of sand liquefaction in sites with similar geological conditions is provided.

关 键 词：砂土液化 标准贯入试验法(SPT) 绝对差值百分比(APD) 距离判别分析法(DDA) 综合分析评价 

分 类 号：TU43[建筑科学—岩土工程]