土工膜应变计的研制及其应用(Ⅰ):研制

土工膜应变计作为监测软土地基的一种加固材料——土工织物(土工膜)变形的新型测试手段,经过国家“七五”、“八五”科技攻关研究,解决了将该应变计应用于监测土工织物这类低弹模柔性材料大应变的一系列特殊技术难题;克服长标距特种大应变计的粘贴难点,探讨合理的粘贴方法,使其在土工膜上的粘贴达到最佳效果;寻求合适的低弹模应变胶,要求其固化后的力学特性与被测土工膜材料的力学特性相接近;采用特殊的率定方法对粘贴上特种应变计的土工膜材料进行率定,以求得特种应变计的灵敏系数k和土工膜材料特性A这两项重要参数;以及解决现场实测埋设中的安装、防护等难题。经过攻关研究,使得单薄、脆弱的特种大应变计能够成为可靠、耐用的新型测试手段,应用于三峡工程二期围堰监测防渗土工膜的变形,取得了满意的监测成果。

Development of geomembrane strain gauge and its application ( Ⅰ ): gauges

Geomembrane strain gauge is a new kind of instrument used to measure strain of geomembrane. The key techniques in measuring large strain for the materials with low elastic modulus such as geotextiles and geomembranes were solved in the Chinese National 7th and 8th Five-Year Key Science and Technology Research Project. These techniques involved developing special method to achieve best sticking effect, seeking appropriate glue with the same lower modulus after being solidified to be compatible with geomembrane; developing new method in calibrating the gauge to get the two key parameters ( sensitivity coefficient k, and property index of geomebrane A) and solving problems in installation and protection. The gauge is reliable and durable in rigorous environment. It was used in-situ with good performance to monitor the strain of geomembrane in the 2nd-stage upstream cofferdam for Three Georges Project in May 1998.