深部土与立井井壁竖向相互作用试验台研制及初步应用

Development and preliminary application for test rig of the vertical interaction between deep soil and shaft lining

本文研制成功了一种适用于深部土与立井井壁竖向相互作用研究的试验台,开展了饱和砂土与C60混凝土井壁竖向相互作用初步研究。试验台最大有效试验空间为820 mm×820 mm,最大设计承载能力24 MPa,研究土层深度可达1 200 m。针对饱和砂土与C60混凝土界面的竖向剪切试验表明：当界面法向正应力均值取0.2-0.4 MPa时,剪切应力与剪切位移曲线可采用弹塑性模型加以描述,界面产生相互错动时对应的剪切位移约为0.53-1.11 mm,界面极限静摩擦因数为0.70-0.53,界面抗剪强度值约在140-210 k Pa之间。

In this article, a test rig applying to research on the vertical interaction between deep soil and shaft lining has been developed successfully. Vertical interaction test between saturated sand and C60 concrete shaft lining has been studied preliminarily. The test rig has three main technical parameters： the maximum effective test space is 820 mm×820 mm, the maximum pressure capacity is 24 MPa and the maximum depth of research soil is 1 200 m. The vertical shear test between saturated sand and C60 concrete interface shows that when the average interface normal stress is 0.2-0.4 MPa, the shear stress-shear displacement curve can be described by elastic-plastic model. The maximum shear displacement is about 0.53-1.11 mm. The ultimate static friction coefficient is 0.70-0.53 and the interface shear strength is 140-210 k Pa.