非稳定承压水降水引起土层沉降分布规律分析
|
摘要
承压含水层减压降水实质上是一个卸荷过程,其上覆土层沉降可用基于弹性半无限空间Mindlin位移解的推导公式进行计算.分析表明:无限承压含水层非稳定渗流降水时间对土层沉降影响显著;由承压水减压降水引起的土层分层沉降随距地表距离的增加而增大,最大值位于承压含水层顶板处;影响上覆土层沉降的7个参数中,泊松比和承压含水层渗透系数的变化对土层沉降影响很小;上覆土层厚度、承压含水层厚度越大地表沉降值越小;上覆土层弹性模量较小时对地表沉降影响较大,随着弹性模量的增加,其对地表沉降的影响逐渐减弱;地表沉降随单井出水量、承压水水头降深的增大而增加且近似成线性关系;单井出水量、承压含水层厚度、承压水水头降深、上覆土层弹性模量不仅影响地表沉降值的大小,还会影响地表沉降的空间分布.
Decompression and dewatering in confined aquifer is essentially an unloading process,and the overlaying soil settlement of confined aquifer can be calculated with the derive formulas based on the elastic half-space of Mindlin displacement solution.Analysis shows that influence of dewatering time of unsteady seepage in infinite confined aquifer on soil settlement is significant in comparison with the steady seepage.Soil settlement caused by decompression and dewatering of confined water increases with the increase of the distance to the ground and the maximum value emerges on the roof of the confined aquifer.Of the seven parameters affecting the ground settlement,Poisson ratio and the confined aquifer permeability coefficient affect the ground settlement little.Ground settlement decreases gradually with the increase of overlaying soil thickness and the confined aquifer thickness.The influence of elastic modulus on ground settlement,which is great when its value is small,gradually weakens with the increase of elastic modulus.Ground settlement increases with the increase of out-water volume of single well and water head drawdown,furthermore,a quasi linear relationship exists between them.The out-water volume of single well,the confined aquifer thickness,the water head drawdown and the elastic modulus of overlaying soil affect not only the value of ground settlement,but also the spatial distribution of ground settlement.
Decompression and dewatering in confined aquifer is essentially an unloading process,and the overlaying soil settlement of confined aquifer can be calculated with the derive formulas based on the elastic half-space of Mindlin displacement solution.Analysis shows that influence of dewatering time of unsteady seepage in infinite confined aquifer on soil settlement is significant in comparison with the steady seepage.Soil settlement caused by decompression and dewatering of confined water increases with the increase of the distance to the ground and the maximum value emerges on the roof of the confined aquifer.Of the seven parameters affecting the ground settlement,Poisson ratio and the confined aquifer permeability coefficient affect the ground settlement little.Ground settlement decreases gradually with the increase of overlaying soil thickness and the confined aquifer thickness.The influence of elastic modulus on ground settlement,which is great when its value is small,gradually weakens with the increase of elastic modulus.Ground settlement increases with the increase of out-water volume of single well and water head drawdown,furthermore,a quasi linear relationship exists between them.The out-water volume of single well,the confined aquifer thickness,the water head drawdown and the elastic modulus of overlaying soil affect not only the value of ground settlement,but also the spatial distribution of ground settlement.
引文
[1]张永波,孙新忠.基坑降水工程[M].北京:地震出版社,2000.ZHANG Yongbo,SUN Xinzhong.Dewatering project offoundation pit[M].Beijing:Seismological Press,2000.
[2]李涛,王超.高承压水地层开挖基坑地板隆起稳定性分析[J].岩土工程学报,2009,31(8):1236.LI Tao,WANG Chao.Bottom heave stability duringfoundation pit excavation in soil layer with high artesian waterpressure[J].Chinese Journ al of Geotechnical Engineering,2009,31(8):1236.
[3]Mindlin R D.On the equation of elastic materials with micro-structure[J].International Journal of Solids and Structure,1965,2(1):73.
[4]骆祖江,李会中,付延玲.第四纪松散沉积层地下水渗流与地面沉降控制数值模拟[M].北京:科学出版社,2009.LUO Zujiang,LI Huizhong,FU Yanling.The numericalsimulation of groundwater seepage and ground settlement ofQuaternary loose sediment layer[M].Beijing:Science Press,2009.
[5]周志芳,朱宏高,陈静,等.深基坑降水与沉降的非线性耦合计算[J].岩土力学,2004,25(12):1984.ZHOU Zhifang,ZHU Honggao,CHEN Jing,et al.Nonlinearcoupling calculation between dewatering and settlement ofdeep foundation pits[J].Rock and Soil Mechanics,2004,25(12):1984.
[6]WANG J X,HU L S,WU L G,et al.Hydraulic barrier functionof the underground continuous concrete wall in the pit ofsubway station and its optimization[J].EnvironmentalGeology,2009,57(2):447.
[7]CHAI Jingchun,SHEN Shuilong,ZHU Hehua,et al.Landsubsidence due to groundwater drawdowning Shanghai[J].Geotechnique,2004,54(3):143.
[8]骆冠勇,潘泓,曹洪,等.承压水减压降水引起的沉降分析[J].岩土力学,2004,25(2):196.LUO Guanyong,PAN Hong,CAO Hong,et al.Analysis ofsettlements caused by decompression of confined water[J].Rock and Soil Mechanics,2004,25(2):196.
[9]龚晓南,张杰.承压水降压引起的上覆土层沉降分析[J].岩土工程学报,2011,33(1):145.GONG Xiaonan,ZHANG Jie.Settlement of overlaying soilcaused by decompression of confined water[J].ChineseJournal of Geotechnical Engineering,2011,33(1):145.
[10]王建秀,吴林高,朱雁飞,等.地铁车站深基坑降水诱发沉降机制及计算方法[J].岩石力学与工程学报,2009,28(5):1010.WANG Jianxiu,WU Lingao,ZHU Yanfei,et al.Mechanism ofdewatering-induced ground subsidence in deep subway stationpit and calculation method[J].Chinese Journal of RockMechanics and Engineering,2009,28(5):1010.
[11]金小荣,俞建霖,祝哨晨,等.基坑降水引起周围土体沉降形状分析[J].岩土力学,2005,26(10):1575.JIN Xiaorong,YU Jianlin,ZHU Shaochen,et al.Analysis ofbehaviors of settlement of pit’s surrounding soils bydewatering[J].Rock and Soil Mechanics,2005,26(10):1575.
[12]吴林高.工程降水设计施工与基坑渗流理论[M].北京:人民交通出版社,2003.WU Lingao.Engineering dewatering design and constructionand foundation pit’s seepage theory[M].Beijing:ChinaCommunications Press,2003.
[2]李涛,王超.高承压水地层开挖基坑地板隆起稳定性分析[J].岩土工程学报,2009,31(8):1236.LI Tao,WANG Chao.Bottom heave stability duringfoundation pit excavation in soil layer with high artesian waterpressure[J].Chinese Journ al of Geotechnical Engineering,2009,31(8):1236.
[3]Mindlin R D.On the equation of elastic materials with micro-structure[J].International Journal of Solids and Structure,1965,2(1):73.
[4]骆祖江,李会中,付延玲.第四纪松散沉积层地下水渗流与地面沉降控制数值模拟[M].北京:科学出版社,2009.LUO Zujiang,LI Huizhong,FU Yanling.The numericalsimulation of groundwater seepage and ground settlement ofQuaternary loose sediment layer[M].Beijing:Science Press,2009.
[5]周志芳,朱宏高,陈静,等.深基坑降水与沉降的非线性耦合计算[J].岩土力学,2004,25(12):1984.ZHOU Zhifang,ZHU Honggao,CHEN Jing,et al.Nonlinearcoupling calculation between dewatering and settlement ofdeep foundation pits[J].Rock and Soil Mechanics,2004,25(12):1984.
[6]WANG J X,HU L S,WU L G,et al.Hydraulic barrier functionof the underground continuous concrete wall in the pit ofsubway station and its optimization[J].EnvironmentalGeology,2009,57(2):447.
[7]CHAI Jingchun,SHEN Shuilong,ZHU Hehua,et al.Landsubsidence due to groundwater drawdowning Shanghai[J].Geotechnique,2004,54(3):143.
[8]骆冠勇,潘泓,曹洪,等.承压水减压降水引起的沉降分析[J].岩土力学,2004,25(2):196.LUO Guanyong,PAN Hong,CAO Hong,et al.Analysis ofsettlements caused by decompression of confined water[J].Rock and Soil Mechanics,2004,25(2):196.
[9]龚晓南,张杰.承压水降压引起的上覆土层沉降分析[J].岩土工程学报,2011,33(1):145.GONG Xiaonan,ZHANG Jie.Settlement of overlaying soilcaused by decompression of confined water[J].ChineseJournal of Geotechnical Engineering,2011,33(1):145.
[10]王建秀,吴林高,朱雁飞,等.地铁车站深基坑降水诱发沉降机制及计算方法[J].岩石力学与工程学报,2009,28(5):1010.WANG Jianxiu,WU Lingao,ZHU Yanfei,et al.Mechanism ofdewatering-induced ground subsidence in deep subway stationpit and calculation method[J].Chinese Journal of RockMechanics and Engineering,2009,28(5):1010.
[11]金小荣,俞建霖,祝哨晨,等.基坑降水引起周围土体沉降形状分析[J].岩土力学,2005,26(10):1575.JIN Xiaorong,YU Jianlin,ZHU Shaochen,et al.Analysis ofbehaviors of settlement of pit’s surrounding soils bydewatering[J].Rock and Soil Mechanics,2005,26(10):1575.
[12]吴林高.工程降水设计施工与基坑渗流理论[M].北京:人民交通出版社,2003.WU Lingao.Engineering dewatering design and constructionand foundation pit’s seepage theory[M].Beijing:ChinaCommunications Press,2003.
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心