循环荷载作用下砂土-结构物仿生界面剪切特性研究  

Shear characteristics of biomimetic sand-structure interface under cyclic loading conditions

作　　者：曹苏南 李春红 陈远兵 费康[1] CAO Su-nan;LI Chun-hong;CHEN Yuan-bing;FEI Kang(College of Architectural Science and Engineering,Yangzhou University,Yangzhou,Jiangsu 225127,China;Yangzhou Water Conservancy Construction Engineering Co.,Ltd.,Yangzhou,Jiangsu 225009,China)

机构地区：[1]扬州大学建筑科学与工程学院,江苏扬州225127 [2]扬州水利建筑工程有限责任公司,江苏扬州225009

出　　处：《岩土力学》2025年第3期821-832,共12页Rock and Soil Mechanics

基　　金：国家自然科学基金项目(No.52108345);江苏省(扬州大学)研究生科研与实践创新计划项目(No.KYCX23_3539)。

摘　　要：海上抗拔基础等工程可以利用蛇皮仿生界面正反摩擦异性提升承载性能,此类界面实际可能承受波浪、地震等循环荷载。为了解循环荷载作用下土-结构物仿生界面的正反摩擦异性特征,基于界面循环剪切仪,开展系列砂土-结构物仿生界面循环直剪试验,研究循环初始位置、法向应力、仿生界面表观形态、砂土相对密实度对循环剪切各向异性的影响规律,初步探讨循环后的抗剪强度演化特性。研究结果表明,循环初始位置和法向应力增大均导致界面颅向→尾向循环路径下剪切各向异性增大,尾向→颅向路径下剪切各向异性减小;界面鳞片长度与高度的比值对中等密实下的仿生界面剪切各向异性影响不明显;但是砂土相对密实度增大,此比值对颅向→尾向循环剪切路径下的剪切各向异性影响显著增大,对尾向→颅向循环路径下剪切各向异性影响略微增加。恒定应力条件下,经过两种循环路径后的仿生界面单向剪切峰值强度均大于未经历循环的单向剪切峰值强度,界面峰值摩擦角也明显增加。研究成果将为相关工程的优化应用提供重要参考。The directional frictional anisotropy of snake-skin-inspired interfaces has great potential to improve the load-bearing performance of offshore uplift pile foundations and other engineering applications.Such interfaces are designed to withstand cyclic loads,including those induced by waves and earthquakes.To investigate the characteristics of directional frictional anisotropy of soil-structure bio-inspired interfaces under cyclic loading,a series of cyclic direct shear tests were conducted using an advanced interface cyclic shear apparatus.The study examined the effects of initial cyclic position,normal stress,bio-inspired interface morphology,and sand density on cyclic shear anisotropy,along with an initial exploration of shear strength characteristics following cyclic loading.The findings revealed that increasing initial position of the cycle and normal stress enhanced shear anisotropy under the cranial-caudal cyclic loading path,while reducing shear anisotropy under the caudal-cranial cyclic loading path.For interfaces at moderate densities,variations in the ratio of interface scale length to height exhibited negligible effects on shear anisotropy.However,as sand density increased,the influence of this ratio on shear anisotropy became more pronounced under the cranial-caudal cyclic shear path,with a slightly increased effect observed under the caudal-cranial cyclic path.Under constant stress conditions,the peak shear strengths in monotonic shear tests of the bio-inspired interfaces following both types of cyclic shear paths exceeded those observed without prior cyclic shearing,and it was also found that the peak interface friction angle increased significantly.These findings provide valuable insights for the optimization and practical application of bio-inspired interfaces in engineering projects.

关 键 词：砂土 仿生界面 循环荷载 剪切各向异性 抗剪强度 

分 类 号：TU441[建筑科学—岩土工程]