大屯水库土工膜气胀变形影响因素分析
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摘要
大屯水库围坝坝基采用库底全铺土工膜的水平防渗方案,在地下水位、土工膜损伤、温度等因素的影响下,膜下非饱和土层气场会发生变化,产生土工膜气胀甚至胀破现象。为分析大屯水库气胀变形影响因素,将土工膜气胀受力变形简化为环向约束条件下的土工膜气胀变形,研制了环向约束条件下土工膜气胀变形试验设备,开展了土工膜气胀变形影响因素的试验研究。研究表明:试验设备的孔径、加载速率、土工膜厚度是影响土工膜气胀变形的主要因素,土工膜损伤、温度也对土工膜气胀变形产生一定的影响。
A horizontal seepage control scheme in Datun Reservoir is completely lined with geomembranes. The gas field in unsaturated soilwill be changed by the factors such as the groundwater level,geomembrane defects and temperature and then the phenomenon of air expan-sion and even burst will be happened. In order to analyze the influencing factors of geomembrane air expansion deformation of Datun Reser-voir,the forced deformation of geomembrane air expansion was simplified as geomembrane air expansion deformation under the ring-restrain-ed conditions,a test apparatus was developed and some tests were conducted to study the influencing factors of geomembrane air expansiondeformation. Some other influencing factors on geomembrane air expansion deformation were analyzed subsequently. The results of tests and a-nalysis show that the test apparatus,loading rate and geomembrane thickness are the major factors that will influence the degree of geomem-brane air expansion deformation and geomembrane defect and temperature also have an effect on the geomembrane air expansion deformation.
A horizontal seepage control scheme in Datun Reservoir is completely lined with geomembranes. The gas field in unsaturated soilwill be changed by the factors such as the groundwater level,geomembrane defects and temperature and then the phenomenon of air expan-sion and even burst will be happened. In order to analyze the influencing factors of geomembrane air expansion deformation of Datun Reser-voir,the forced deformation of geomembrane air expansion was simplified as geomembrane air expansion deformation under the ring-restrain-ed conditions,a test apparatus was developed and some tests were conducted to study the influencing factors of geomembrane air expansiondeformation. Some other influencing factors on geomembrane air expansion deformation were analyzed subsequently. The results of tests and a-nalysis show that the test apparatus,loading rate and geomembrane thickness are the major factors that will influence the degree of geomem-brane air expansion deformation and geomembrane defect and temperature also have an effect on the geomembrane air expansion deformation.
引文
[1]CAO X S,YUAN J P,HEG L,et al.In Situ Test and Anal-ysis Method of Air Bulging Under Geomembranes in A Shal-low-lined Reservoir[J].Geotextiles and Geomembranes,2015,43(1):24-34.
[2]李旺林,李志强,魏晓燕,等.土工膜缺陷渗漏引起的气胀研究[J].岩土工程学报,2013,35(6):1161-1165.
[3]束一鸣,叶乃虎.LDPE土工膜液胀极限荷载的工程仿真实验[J].水利水电科技进展,2013,23(5):1-3.
[4]AYA T,NAKAYARNA T.Influence of Environmental Tem-perature on Yield Stress of Polymer[J].JSME InternationalJournal(Senes A),1997,40(3):343-348.
[5]MERAH N,SAGHIR F,KHAN Z,et al.Effect of Tempera-ture on Tensile Properties of HDPE Pipe Material[J].Plast,Rubber,Composites,2006,35:226-230.
[6]IMAIZUMI S,KAWAMATA K,TSUBOI M.Study on Ther-mal Stress Within the Geomembrane Liner Induced by Tem-perature Decrease[C]//Proceedings of the 7th InternationalLandfill Symposium.Sardinia:CISA,1999:115-122.
[2]李旺林,李志强,魏晓燕,等.土工膜缺陷渗漏引起的气胀研究[J].岩土工程学报,2013,35(6):1161-1165.
[3]束一鸣,叶乃虎.LDPE土工膜液胀极限荷载的工程仿真实验[J].水利水电科技进展,2013,23(5):1-3.
[4]AYA T,NAKAYARNA T.Influence of Environmental Tem-perature on Yield Stress of Polymer[J].JSME InternationalJournal(Senes A),1997,40(3):343-348.
[5]MERAH N,SAGHIR F,KHAN Z,et al.Effect of Tempera-ture on Tensile Properties of HDPE Pipe Material[J].Plast,Rubber,Composites,2006,35:226-230.
[6]IMAIZUMI S,KAWAMATA K,TSUBOI M.Study on Ther-mal Stress Within the Geomembrane Liner Induced by Tem-perature Decrease[C]//Proceedings of the 7th InternationalLandfill Symposium.Sardinia:CISA,1999:115-122.