球模仪测试冻结砂长期抗剪强度的双球模型解答及其试验研究  

The solution of the double-sphere model and experimental research of the long-term shear strength of frozen sand based on spherical template indenter test

作　　者：恽晴飞 谢春磊 张泽 刘有乾 付峻松 刘启 YUN Qingfei;XIE Chunlei;ZHANG Ze;LIU Youqian;FU Junsong;LIU Qi(Shanghai Changkai Geotechnical Engineering Co.Ltd.,Shanghai 200093,China;College of Civil Engineering,Northeast Forestry University School of Civil Engineering/School of Traffic and Transportation/Cold Region Science and Engineering Research Institute,Harbin 150040,China;College of Civil Engineering and Mechanics,Lanzhou University,Lanzhou 730000,China;State Key Laboratory of Frozen Soil Engineering,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China;Inner Mongolia Autonomous Region Traffic Construction Engineering Quality Monitoring and Appraisal Station Hohhot 010051,China;China Railway Qinghai-Tibet Group Co.Ltd.,Xining 810000,China)

机构地区：[1]上海长凯岩土工程有限公司,上海200093 [2]东北林业大学土木工程学院/交通学院/寒区科学与工程研究院,黑龙江哈尔滨150040 [3]兰州大学土木工程与力学学院,甘肃兰州730000 [4]中国科学院西北生态环境资源研究院冻土工程国家重点实验室,甘肃兰州730000 [5]内蒙古自治区交通建设工程质量监测鉴定站,内蒙古呼和浩特010051 [6]中国铁路青藏集团有限公司,青海西宁810000

出　　处：《冰川冻土》2022年第2期485-494,共10页Journal of Glaciology and Geocryology

基　　金：黑龙江省交通投资集团有限公司科研项目(JT-100000-ZC-FW-2021-0129);国家自然科学基金委员会(NSFC)与俄罗斯基础研究基金会(RFBR)合作交流项目(42011530083);青藏集团公司科技研究开发计划项目(QZ2021-G03)资助。

摘　　要：球形模板压入试验由于其试验过程简单易行,测试结果比较准确而广泛应用于冻结土的力学性质测试中,尤其是在确定冻结土的等效黏聚力上优势更为显著。本文通过球形模板压入试验分析不同粒径组冻结砂土长期等效黏聚力(长期抗剪强度)随时间的变化规律,并利用弹性力学解答空间问题的研究方法,总结出不同固定荷载试验条件下球形模板压头压入冻结砂土试样深度S_(t)之间的相互转换关系。研究结果表明:试验过程中,冻结砂土的长期抗剪强度随时间呈降低趋势,降低速率由快至慢,最终在试验进行约24h后趋于稳定,且冻结砂土长期抗剪强度与砂土的颗粒尺寸呈正相关的关系;在7.0kg固定荷载试验条件下得到的压入深度随时间变化曲线经转换后得到的拟合曲线与在5.1kg固定荷载试验条件下得到的压入深度随时间变化的实测曲线相比较,具有较高拟合度;不同粒径组拟合所得的冻结砂土长期抗剪强度随时间变化曲线也与实测曲线具有较高拟合度。The distribution of frozen soil in our country is very broad,and the area of permafrost alone accounts for 22.4%of the total land area.As a special kind of soil,frozen soil has many properties that thawing soil does not have due to the influence of ice cement in the soil.Among the many properties of frozen soil,the deformation and strength of frozen soil are the basic problems affecting engineering construction in frozen soil areas.The spherical template indenter test is widely used in the test of the mechanical properties of frozen soil because of its simple test process and relatively accurate test results.Compared with the conventional triaxial test or direct shear test,the test process of the spherical template indenter test is simple and easy to implement,the test period is short,and the sample preparation requirements are low.The advantage of effective cohesion is more significant.Therefore,based on the spherical template indenter test of the frozen soil,this paper estimates the strength and mechanical index of the soil through the indentation depth of the spherical template indenter test,and establishes the relationship between the force of the sample and the indentation depth of the indenter test.The specific test method is as follows:take the water-saturated frozen sandy soil made of different particle size groups(the moisture content of the sample is affected by the particle size in the saturated state)as the research object,study the variation law of the depth of the frozen soil sample pressed into the soil by the spherical indenter with time under the conditions of different fixed loads.By comparing and referring to the frozen sands of each particle size group,the long-term equivalent cohesion of the frozen sands of different particle size groups is summarized.The change law of force(long-term shear strength)with time,and the research method of elastic mechanics to solve space problems,summed up the mutual conversion between the depth S_(t)of spherical template indenters pressed into frozen sand sampl

关 键 词：球模仪 抗剪强度 冻结砂土 长期强度 双球模型 

分 类 号：P642.14[天文地球—工程地质学] TU445[天文地球—地质矿产勘探]