论文部分内容阅读
将研制的土工膜应变计应用于三峡工程二期上游围堰现场,以监测防渗土工膜在工程中产生的实际应变,并获得了满意的大应变监测成果。埋设于上游围堰不同高程的18支土工膜应变计,在较长时段内,不仅全部观测到防渗土工膜在施工阶段围堰填土碾压产生的应变规律,如0+500断面的10支土工膜应变计均测得11%～19%的大应变值,而且大部份应变计一直工作到极限量程才损坏。其中除了0+500断面因施工加载速率过快而导致防渗土工膜较早产生较大的变形,使得10支应变计在埋设后的施工填土3个多月内即陆续超量程损坏之外,其余的土工膜应变计工作寿命长达3年多。埋设于0+500子堰和0+930断面的土工膜应变计,在2000年和2001年夏季汛期中及汛期后,有些监测点的应变陡增到16%～20%之间,据此可以推测,此时该测点处的堰体产生了较大的变形。防渗土工膜的应变监测结果不仅与围堰构筑时的加载速率相关,并与围堰拆除时所发现的变形情况相吻合。
The developed geomembrane strain gauge is applied to the site of the upstream cofferdam of the second phase of the Three Gorges Project to monitor the actual strain produced by the seepage-proof geomembrane in the project and achieve satisfactory results of monitoring large strain. Buried in the upstream cofferdam of different elevation of 18 geomembrane strain gauge, in a longer period of time, not only all observed impermeable geomembrane in the construction phase cofferdam filling the rolling law of strain, such as 0 +500 section 10 Geomembrane strain gauges were measured 11% to 19% of the large strain value, and most of the strain gauge has been working until the limit range before damage. In addition to the 0 +500 section due to the construction of the loading rate is too fast and lead to seepage geomembrane larger deformation earlier, so that 10 Strain Gauge buried in the construction of more than three months after construction that is gradually over range damage , The remaining geomembrane strain gauge working life up to 3 years. Geomembrane strain gauges buried at 0 +500 weirs and 0 + 930 sections show a sharp increase in strain at some monitoring points between 16% and 20% during the summer and winter flood season in 2000 and 2001, Presumably, at this point of the weir at the measuring point had a greater deformation. The monitoring results of the seepage-proof geomembrane strain are not only related to the loading rate of cofferdam construction, but also coincide with the deformation conditions found when the cofferdam is demolished.