饱和粉土液化及液化后力学特性试验研究
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摘要
对饱和粉土进行了一系列动三轴液化及液化后试验,即进行饱和粉土液化试验及在饱和粉土液化后孔隙水压力进行了不同程度消散后,再进行三轴剪切试验。探讨了饱和粉土的液化特性以及液化后孔压消散程度对液化后粉土力学特性的影响规律。试验结果表明:饱和粉土的抗液化强度随着所施加动应力幅值的增大而减小;液化后饱和粉土孔压消散程度越大(即再固结程度越大),则液化后粉土的不排水抗剪强度越大,其应力应变关系曲线表现为应变硬化型,土体的切线模量随着应变的增大而减小;液化后粉土的孔压进行了不同程度消散后,再进行的三轴剪切试验中应力应变关系呈对数曲线关系。
A series of dynamic triaxial liquefaction and post-liquefaction tests are carried out on saturated silt soil. That is, liquefaction tests are done on saturated silt soil and then triaxial shear tests are conducted on the liquefied saturated silt soil after the pore water pressure has dissipated to some extent. The liquefaction characteristics of saturated silt soil are discussed and the influencing rule of the degree of pore pressure dissipation after liquefaction on the mechanical properties of liquefied saturated silt soil is explored. The test results show that the liquefaction resistance of saturated silt soil decreases with the increase of the applied dynamic stress amplitude; The greater the degree of pore pressure dissipation of saturated silt soil after liquefaction(i.e., the greater the degree of re-consolidation), the greater the undrained shear strength of the silt soil after liquefaction, the stress-strain relationship curve is of strain-hardening type, and the tangent modulus of the soil decreases with the increase of strain; after the liquefaction, the pore pressure of the silt soil is dissipated to varying degrees, and the stress-strain relationship in the triaxial shear test is logarithmic.
A series of dynamic triaxial liquefaction and post-liquefaction tests are carried out on saturated silt soil. That is, liquefaction tests are done on saturated silt soil and then triaxial shear tests are conducted on the liquefied saturated silt soil after the pore water pressure has dissipated to some extent. The liquefaction characteristics of saturated silt soil are discussed and the influencing rule of the degree of pore pressure dissipation after liquefaction on the mechanical properties of liquefied saturated silt soil is explored. The test results show that the liquefaction resistance of saturated silt soil decreases with the increase of the applied dynamic stress amplitude; The greater the degree of pore pressure dissipation of saturated silt soil after liquefaction(i.e., the greater the degree of re-consolidation), the greater the undrained shear strength of the silt soil after liquefaction, the stress-strain relationship curve is of strain-hardening type, and the tangent modulus of the soil decreases with the increase of strain; after the liquefaction, the pore pressure of the silt soil is dissipated to varying degrees, and the stress-strain relationship in the triaxial shear test is logarithmic.
引文
[1]黄博,陈云敏,殷建华,等.控制试样初始剪切模量的动三轴液化试验[J].岩土工程学报,2000(6):682-685.
[2]何丽梅.饱和粉土液化特性试验研究[D].成都:西南交通大学,2007.
[3]杨秀娟.黄河三角洲粉质土振动孔隙水压力发展规律试验研究[J].水运工程,2010(6):1287-1290.
[4]常方强,贾永刚.黄河口不同强度粉土液化特性的试验研究[J].岩土力学,2011(9):2692-2696.
[5] Polito C P,Ii J R M.Effects of Non plastic Fines on the Liquefaction Resistance of Sands[J].Journal of Geotechnical&Geo environmental Engineering,2003(5):408-415.
[6]杨永香,贾景超,黄志全.饱和非纯净砂土液化特性研究进展[J].华北水利水电学院学报,2012(2):111-115.
[7] Soroush A,Soltani-Jigheh H.Pre-and post-cyclic behavior of mixed clayey soils[J].Canadian Geotechnical Journal,2009(2):115-128.
[8] Yasuhara K,Hirao K,Hyde A F L. Effects of cyclic loading on undrained strength and compressibility of clay[J].Soils and Foundations,1992(1):107-116.
[9] Yasuhara K,Murakami S,Song B W,etal. Postcyclic Degradation of Strength and Stiffness for Low Plasticity Silt[J].Journal of Geotechnical and Geo-environmental Engineering,2003(8):756-769.
[10]曾长女.细粒含量对粉土液化及液化后影响的试验研究[D].南京:河海大学,2006.
[11]刘汉龙,曾长女,周云东.饱和粉土液化后变形特性试验研究[J].岩土力学,2007(9):1866-1870.
[2]何丽梅.饱和粉土液化特性试验研究[D].成都:西南交通大学,2007.
[3]杨秀娟.黄河三角洲粉质土振动孔隙水压力发展规律试验研究[J].水运工程,2010(6):1287-1290.
[4]常方强,贾永刚.黄河口不同强度粉土液化特性的试验研究[J].岩土力学,2011(9):2692-2696.
[5] Polito C P,Ii J R M.Effects of Non plastic Fines on the Liquefaction Resistance of Sands[J].Journal of Geotechnical&Geo environmental Engineering,2003(5):408-415.
[6]杨永香,贾景超,黄志全.饱和非纯净砂土液化特性研究进展[J].华北水利水电学院学报,2012(2):111-115.
[7] Soroush A,Soltani-Jigheh H.Pre-and post-cyclic behavior of mixed clayey soils[J].Canadian Geotechnical Journal,2009(2):115-128.
[8] Yasuhara K,Hirao K,Hyde A F L. Effects of cyclic loading on undrained strength and compressibility of clay[J].Soils and Foundations,1992(1):107-116.
[9] Yasuhara K,Murakami S,Song B W,etal. Postcyclic Degradation of Strength and Stiffness for Low Plasticity Silt[J].Journal of Geotechnical and Geo-environmental Engineering,2003(8):756-769.
[10]曾长女.细粒含量对粉土液化及液化后影响的试验研究[D].南京:河海大学,2006.
[11]刘汉龙,曾长女,周云东.饱和粉土液化后变形特性试验研究[J].岩土力学,2007(9):1866-1870.