MD RASEL Ahammed,邓刚,张延亿,胡敏云,张茵琪

• 1:中国水利水电科学研究院流域水循环模拟与调控国家重点实验室
• 2:中国水利水电科学研究院水利部水工程建设与安全重点实验室
• 3:中国水利水电科学研究院水利部白蚁防治重点实验室

摘要(Abstract)：

【目的】砂是一种常见的建筑材料，在水利水电工程、交通、海洋和其他土木工程中应用广泛。在不同的工程应用中，砂土经受不同的加载过程和加载速率。因为加载速率效应，砂在相同幅值荷载作用下产生的变形有一定差异。这项研究旨在深入了解不同应变速率三轴剪切条件下砂的应力应变特性。【方法】采用相对密度为0.9的密砂，开展了一系列三轴固结排水剪切试验，在两种不同围压(750 kPa和2 000 kPa)下对试样进行固结后，分别采用三种不同的常应变速率(0.006 25%/min, 0.062 5%/min和0.625%/min)进行应变控制排水剪切。根据试验数据，绘制了应力-应变关系发展曲线，分析了应变速率对砂土偏应力和体积应变演化的影响。【结果】结果表明，在本试验采用的恒定应变速率和围压条件下，密砂在轴向应变约为2%时将发生屈服。屈服前，相同轴应变增量对应的土样偏应力增量和体积应变增量对剪切速率比较敏感，特别是体积应变，即加载应变速率较小时获得的土样剪应力较低，但体积应变(收缩)发展量较大。【结论】在屈服前，砂土的模量随着加载速率的增加而增大；但是屈服后，当加载达到大应变(ε_1=15%)条件时，应变率对砂土应力变形的影响不明显。另外，在相同围压下，以不同应变率加载的砂样在加载过程中的应力比(q/p)-偏应变关系呈现出一致性。该研究可以提高对砂土力学特性的认识，并为砂土地基上的结构设计和安全评价提供参考。

关键词(KeyWords)： 密砂;三轴固结排水试验;应变率;偏应力;体积应变;变形;力学性能;影响因素

Abstract:

Keywords:

基金项目(Foundation): National Key Research and Development Plan Project(2022YFC3005501);; Basic research expenses of China Institute of Water Resources And Hydropower Research(GE0145B032021,GE110145B0032023)~~

作者(Author): MD RASEL Ahammed,邓刚,张延亿,胡敏云,张茵琪

DOI: 10.13928/j.cnki.wrahe.2024.05.005

参考文献(References)：

• [1] ABRANTES A E,JERRY A Yamamuro.Experimental and data analysis techniques used for high strain rate tests on cohesionless soil[J].Geotechnical Testing Journal,2002,25(2):128-141.
• [2] LI F L,PENG F L,LI J Z,et al.Strain rate effects on the sand and its quantitative analysis[J].Journal of Central South University 2009,16(4):658-662.
• [3] SUESCUN F E A.Study of Strain Rate Effects on the Mechanical Behavior of Sand[D].New York:Polytechnic Institute of New York University,2016.
• [4] ELGHORAIBY M A,PARK H,MANZARI M T.Stress-strain behavior and liquefaction strength characteristics of Ottawa F65 sand[J].Soil Dynamics and Earthquake Engineering,2020,138:106292.
• [5] BEREN M,COBANOGLU I,CELIK S B,et al.Shear rate effect on strength characteristics of sandy soils[J].Soil Mechanics and Foundation Engineering,2020,57(4):281-287.
• [6] CASAGRANDE A,SHANNON W L.Strength of soils under dynamic loads[J].Proceeding of ASCE,1948,74(4):591-608.
• [7] LEE K L,SEED H B,DUNLOP P.Effect of transient loading on the strength of sand[C]// Publications Committee of VII ICSMEF.Proceedings of 7th International Conference on Soil Mechanic and Foundation Engineering.Scotland:Butterworths,1969:239-247.
• [8] JERRY A Y,ABRANTES A E,LADE P V.Effect of strain rate on the stress-strain behavior of sand [J].Journal of Geotechnical and Geoenvironmental Engineering,2011,137(12):1169-1178.
• [9] TATSUOKA F,UCHIMURA T,HAYANO K,et al.Time-dependent deformation characteristics of stiff geomaterials in engineering practice [C]//JAMIOLKOWSKI M,LANCELLOTA R.Proceeding,2nd International Conference Pre-failure Deformation Characteristics of Geomaterials,Vol.2.Rotterdam,The Netherlands:Balkema,1999:1161-1262.
• [10] MATSUSHITA M,TATSUOKA F,KOSEKI J,et al.Time effects on the pre-peak deformation properties of sands[C]// JAMIOLKOWSKI M,LANCELLOTA R,PRESTI D L.Proceedings of the Second International Conference on Pre-Failure Deformation Characteristics of Geomaterials,IS Torino′ 99.Rotterdam:Balkema,1999:681-689.
• [11] LIGGIO C D.Experimental study and modeling of instability and time effects of granular materials[D].Baltimore:Johns Hopkins University,2001.
• [12] POUL V L,LIGGIO C D,NAM J.Strain rate,creep,and stress drop-creep experiments on crushed coral sand[J].Journal of Geotechnical and Geoenvironmental Engineering,2009,135(7):941-953.
• [13] DIAZ-RODRIGUEZ J,MARTINEZ V J,SANTAMARINA J.Strain-rate effects in Mexico city soil[J].Journal of Geotechnical and Geoenvironmental Engineering,2009,135(2):300-305.
• [14] JERRY A Y,POUL V L.Effects of strain rate on instability of granular soils[J].Geotechnical Testing Journal,1993,16(3):304-313.
• [15] ZHU J,GONG X,ZHOU J,et al.Large-scale triaxial tests on the behavior of gravelly soil at different shearing rates[J].Journal of Hohai University (Natural Sciences),2014,42(1):29-34.
• [16] SU J D,JIANG Z Y,XIA J,et al.Study of influence from the shear rate on shear strength of swamp tukfy soil [J].Water Resources and Hydropower Engineering,2020,51 (7):99-107.
• [17] HUANG W C,ZHANG G K,DENG G,et al.Effect of low speed loading on confined compression deformation of Lianghekou rockfill material [J].Journal of Hydroelectric Engineering,2022,41(6):141-152.
• [18] TSUTSUMI A,TANAKA H.Combined effects of strain rate and temperature on consolidation behavior of clayey soils[J].Soils and Foundations,2012,52(2):207-215.
• [19] YAN Chengqiang,BAI Yufan,XU Yongfu,et al.Unconfined compressive strength and shear strength properties of lime stabilized soil[J].Railway Investigation and Surveying,2023,49(1):102-106.
• [20] MA Zhigang,LI Xuefeng.Study on critical state test characteristics of eolian sand in Tengger Desert[J].Ningxia Engineering Technology,2022,21(3):202-206.
• [21] ROBINSON S,BROWN M J,KNAPETT J et al.Impacts of reference strain rate and strain level dependency on rate effects in fine-grained soils[J].Géotechnique Letters,2023,13(1):48-53.
• [22] HU T,LIU D,CHANG J.Experimental study on strain rate effect of strength characteristics of unsaturated silty clay[J].Case Studies in Construction Materials,2020,12:e00332.
• [23] Ministry of Water Resources of the People′s Republic of China.Standard for Soil Test Methods:GB/ T 50123—2019 [S] Beijing:China Planning Press,2019.
• [24] DE BONO J P,MCDOWELL G R.On the micro mechanics of yielding and hardening of crushable granular soils[J].Computers & Geotechnics,2018,97:167-188.