土工布应变的测量方法研究

A Method of Measuring the Strain of Geotextile

土工布被广泛应用于各种加筋土工程当中,然而由于土工布应变测量难度大、精度低,在工程中发挥了多大的作用,产生了多大的变形尚不明确。针对土工布这类低弹性模量的柔性材料,提出采用柔性胶粘贴电阻应变片,通过对粘合剂粘贴形状与厚度等的精细控制,使得应变片能够与土工布协同变形,实现了土工布应变的准确测量。同时研制了一套用于土工布应力应变标定的设备,可将应变片测值转换为被测土工布的实际受力大小,并将其应用于离心模型试验中。研究结果为下一步研究土工布的加筋机理及其对模袋砂围堰稳定性的影响提供了技术保障。

Despite wide usage in reinforced soil projects,geotextile is featured with big challenge and low precision in strain measurement as it is a flexible material of low elastic modulus. The role of geotextile in engineering as well as the strain of geotextile are still uncertain. In this article,we proposed a method of accurately measuring the strain of geotextile by controlling the shape and thickness of a flexible binder to paste strain gauges,which,hence deforming in coordination with geotextile. Moreover,we also developed an equipment for calibrating the stress-strain of geotextile,by which the observed value of strain gauge can be transformed to the actual deformation of geotextile.The equipment's applicability was verified by centrifugal model test. The research achievement offers technical support for further researches on geotextile's reinforce mechanism and influence on mold bag sand cofferdam stability.