基于循环剪切试验的砥砂岩-混凝土界面剪切特性研究

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关键词：砥砂岩；循环荷载；界面剪切；剪切特性

中图分类号：TU473.1 文献标志码：A 文章编号：1000-0844（2026）01—0048—11

DOI：10.20000/j.1000-0844.20240530002

Shear behavior of Pisha sandstone-concrete interface based on cyclic shear tests

LIU Wei，LIU Qingpeng，YAN Xiaoyu，SUN Xinran （InnerMongoliaUniuersity，HohhotOloo7o，InnerMongolia，China）

Abstract： To investigate the influence of dynamic loads on the shear behavior of the Pisha sandstone-concrete interface， field investigations were carried out on numerous wind turbines and bridges in Ordos City， Inner Mongolia Autonomous Region. The investigations provided data on the layout and embedment depth of concrete piles. Based on these data， shear tests were conducted in the laboratory using a dynamic direct shear apparatus to induce dynamic loading conditions. The effects of load cycle number，shear displacement amplitude，and initial normal load on the shear behavior of the interface were analyzed. Results indicate that as the number of cyclic shear cycles increases， the peak shear stress，dynamic shear stiffness，and damping ratio at the interface undergo a gradual decline. A comparison of the peak shear stresses following the lst and 30th cycles indicates that the maximum decrease in peak shear stress （41.7% ） occurs under an initial normal load of 200kPa and a displacement amplitude of 2mm . Conversely，the smallest decrease in peak shear stress （ 18.5% ）is observed under an initial normal load of 50kPa and a displace ment amplitude of 5mm . Under identical loading conditions， the hysteretic curves of shear stress versus shear displacement exhibit similar characteristics.As the load increases，the normal displacement gradually increases，reaching a maximum value of 1.912mm at an initial normal load of 400kPa and a shear displacement amplitude of 5mm . The soil samples demonstrate a phenomenon of shear shrinkage during the process of shearing，accompanied by a progressive reduction in peak shear stress. The findings can be used to predict the deformation trends of bridges and wind turbines during long-term operation and provide important technical support for ensuring the safe operation of such structures in the Pisha sandstone distribution area of Ordos.

Keywords： Pisha sandstone;cyclic loading;interface shear;shear behavior

0 引言

砥砂岩主要分布在黄土高原北部晋陕蒙接壤地区的鄂尔多斯高原，是一种结构松散的岩体。（剩余13530字）