常/变法向应力作用下密砂-混凝土接触面剪切力学性状试验研究*
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（1 西安建筑科技大学土木工程学院，西安 710055；2 中铁一院集团山东建筑设计院有限公司，威海 264299)［摘要］通过大型直剪仪对密砂-混凝土接触面进行了常法向应力和变法向应力作用下的剪切试验，分析了剪切面剪应力和体应变的变化特征，建立了密砂-混凝土接触面剪切的数学模型。结果表明：在常法向应力剪切试验中，密砂-混凝土接触面的抗剪强度符合摩尔库伦定律，抗剪残余强度与法向应力之间成直线关系，体应变与法向应力密切相关；在变法向应力剪切试验中第二级法向应力作用下，密砂-混凝土接触面的剪应力最大值与相应的常法向应力作用下的抗剪残余强度相同，但其体应变比相应常法向应力作用下的体应变小。在常法向应力作用下，密砂-混凝土接触面的剪应力-剪切位移关系曲线可用三折线拟合；在变法向应力作用下，密砂-混凝土接触面的剪应力-剪切位移关系曲线可用三折线双曲线拟合。［关键词］密砂-混凝土接触面; 大型直剪试验; 剪应力; 体应变; 剪切位移中图分类号：TU43，TU411 文献标识码：A 文章编号：1002-848X(2015)01-0082-05Experimental study on shear mechanical properties on dense sand-concrete interface under constant and varying normal stressCao Weiping1, Lu Qingyuan1, Liang Peng2（1 College of Civil Engineering, Xi’an University of Architecture and Technology, Xi’an 710055, China; 2 Shandong Institute of Architectural Design Co., Ltd. of China Railway First Design Institute Group, Weihai 264299, China）Abstract: A series of large-scale direct shear tests of dense sand-concrete interface under constant and varying normal stress were carried out by using large-scale direct shear apparatus to analyze the characteristics of shear stress and volumetric strain and mathematical models of dense sand-concrete interface were established. The results show that in the constant normal stress-shear tests, the shear strength of dense sand-concrete interface satisfies the Mohr-Coulomb criterion, the relationship between residual strength and normal stress is linear, and the volumetric strain is closely related to the normal stress. Under the second order normal stress of the varying normal stress-shear tests, the maximum shear stress is identical to the residual strength under the constant normal stress but the volumetric strain is smaller. The relationship between the shear stress and the shear displacement under the constant normal stress can be fitted with the tri-linear, and the relation ship between them under the varying normal stress can be fitted with the tri-linearhyperbolic curve.Keywords: dense sand-concrete interface; large-scale direct shear test; shear stress; volumetric strain; shear displacement*国家自然科学基金(51078308)。作者简介：曹卫平，博士，教授，Email：caowp@xauat.edu.cn。参考文献［1］张冬霁，卢廷浩. 一种土与结构接触面模型的建立及其应用［J］. 岩土工程学报，1998，20(6)：62-66.［2］张嘎，张建民. 粗粒土与结构接触面单调力学特性的试验研究［J］. 岩土工程学报，2004，26(1)：21-25.［3］张嘎，张建民. 循环荷载作用下粗粒土与结构接触面变形特性的试验研究［J］. 岩土工程学报，2004，26(2)：254-258.［4］张嘎，张建民. 夹有泥皮粗粒土与结构接触面力学特性试验研究［J］. 岩土力学，2005，26(9)：1374-1378.［5］刘方成，尚守平，王东海. 粉质黏土-混凝土接触面特性单剪试验研究［J］. 岩石力学与工程学报，2011，30(8)：1720-1728.［6］ALONSO E E，JOSA A, LEDESMA A. Negative skin friction on piles: a simplified analysis and prediction procedure［J］. Geotechnique, 1984，34(3)：341-357.［7］FAKHARIAN K, EVGIN E. Cyclic simple-shear behavior of sand-steel interfaces under constant normal stiffness condition［J］. Journal of Geotechnical and Geoenvironmental Engineering, ASCE, 1997, 123(12)：1096-1105.［8］TIWARI B, AJMERA B，KAYA G. Shear strength reduction at soil structure interface［C］// GeoFlorida 2010:Advances in Analysis，Modeling & Design（GSP199）. ASCE，2010：1747-1756.［9］梁鹏，曹卫平，陆清元. 常/变法向应力下松砂-混凝土接触面剪切力学性状试验研究［J］. 建筑结构，2014，44(8):61-65.
