考虑有效电压衰减的二维真空预压联合电渗排水固结解析解
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摘要
以指数函数描述电渗过程中有效电压随时间衰减,建立考虑水平向和竖向的二维真空预压联合电渗排水固结理论,推导超静孔隙水压力的解析解,给出平均固结度的计算公式,并采用数值解进行对比验证。在此基础上,设真空度随地基深度线性减小,分析有效电压衰减速率、残余有效电压及真空度衰减率对地基固结性状的影响。研究表明:电压衰减越慢或残余有效电压越大,地基中的孔压消散越快,最终加固效果越好,但固结速度反而越慢,其中有效电压衰减速率对固结度的影响大于残余有效电压;真空度沿深度的衰减率越大,孔压消散越慢,形成的负超静孔压最大值越小,但对固结度几乎没有影响。
In this paper,a two-dimensional consolidation theory for soft foundation under vacuum preloading combined with electro-osmosis was established,which considers the exponential reduction of the effective voltage with time. Then,an analytical solution for excess pore water pressure was derived,and the calculation formula for average degree of consolidation was given. The accuracy of the proposed analytical solution was evaluated by validating it against numerical solution. Assuming that the vacuum degree is linear decrease along the depth,the influences of the reduction of the effective voltage and the decreasing of the vacuum degree to the consolidation behaviour were analyzed. The results show that the slower the reduction of the effective voltage is,or the larger the residual effective voltage is,the faster the dissipation of the excess pore water pressure and the larger the value of the negative excess pore water pressure in the foundation are,but the slower the consolidation is. Besides,the larger the reduction of the vacuum degree along the vertical drain depth is,the slower the dissipation of the excess pore water pressure and the smaller the value of the maximal negative excess pore water pressure in the foundation are. However,the influence of the reduction of the vacuum degree on the consolidation degrees is little.
In this paper,a two-dimensional consolidation theory for soft foundation under vacuum preloading combined with electro-osmosis was established,which considers the exponential reduction of the effective voltage with time. Then,an analytical solution for excess pore water pressure was derived,and the calculation formula for average degree of consolidation was given. The accuracy of the proposed analytical solution was evaluated by validating it against numerical solution. Assuming that the vacuum degree is linear decrease along the depth,the influences of the reduction of the effective voltage and the decreasing of the vacuum degree to the consolidation behaviour were analyzed. The results show that the slower the reduction of the effective voltage is,or the larger the residual effective voltage is,the faster the dissipation of the excess pore water pressure and the larger the value of the negative excess pore water pressure in the foundation are,but the slower the consolidation is. Besides,the larger the reduction of the vacuum degree along the vertical drain depth is,the slower the dissipation of the excess pore water pressure and the smaller the value of the maximal negative excess pore water pressure in the foundation are. However,the influence of the reduction of the vacuum degree on the consolidation degrees is little.
引文
[1]高志义,张美燕,张健.真空预压联合电渗法室内模型试验研究[J].中国港湾建设,2000,(5):58-61.(GAO Zhiyi,ZHANGMeiyan,ZHANG Jian.Laboratory model test of vacuum preloading in combination with electro-osmotic consolidation[J].China Harbour Engineering,2000,(5):58-61.(in Chinese))
[2]房营光,徐敏,朱忠伟.碱渣土的真空-电渗联合排水固结特性试验研究[J].华南理工大学学报:自然科学版,2006,34(11):70-75.(FANG Yingguang,XU Min,ZHU Zhongwei.Experimental investigation into draining consolidation behavior of soda residue soil under vacuum preloading-electro-osmosis[J].Journal of South China University of Technology:Natural Science,2006,34(11):70-75.(in Chinese))
[3]王柳江,刘斯宏,汪俊波,等.真空预压联合电渗法处理高含水率软土模型试验[J].河海大学学报:自然科学版,2011,39(6):671-675.(WANG Liujiang,LIU Sihong,WANG Junbo,et al.Model test for high-water-content soft soil treatment under vacuum preloading in combination with electroosmosis[J].Journal of Hohai University:Natural Science,2011,39(6):671-675.(in Chinese))
[4]王军,张乐,刘飞禹,等.真空预压-电渗法联合加固软黏土地基试验研究[J].岩石力学与工程学报,2014,33(增2):4 181-4 192.(WANG Jun,ZHANG Le,LIU Feiyu,et al.Experimental study of vacuum preloading combined reinforcement with electro-osmosis in soft clay ground[J].Chinese Journal of Rock Mechanics and Engineering,2014,33(Supp.2):4 181-4 192.(in Chinese))
[5]WANG J,MA J,LIU F,et al.Experimental study on the improvement of marine clay slurry by electroosmosis-vacuum preloading[J].Geotextiles and Geomembranes,2016,44(4):615-622.
[6]孙召花,余湘娟,高明军,等.真空-电渗联合加固技术的固结试验研究[J].岩土工程学报,2017,39(2):250-258.(SUN Zhaohua,YU Xiangjuan,GAO Mingjun,et al.Experimental studies on vacuum preloading incorporated with electro-osmosis consolidation for dredger fill[J].Chinese Journal of Geotechnical Engineering,2017,39(2):250-258.(in Chinese))
[7]PENG J,XIONG X,MAHFOUZ A H,et al.Vacuum preloading combined electroosmotic strengthening of ultra-soft soil[J].Journal of Central South University,2013,20(11):3 282-3 295.
[8]鲍树峰,娄炎,董志良,等.新近吹填淤泥地基真空固结失效原因分析及对策[J].岩土工程学报,2014,36(7):1 350-1 359.(BAOShufeng,LOU Yan,DONG Zhiliang,et al.Causes and countermeasures for vacuum consolidation failure of newly-dredged mud foundation[J].Chinese Journal of Geotechnical Engineering,2014,36(7):1 350-1 359.(in Chinese))
[9]徐伟,刘斯宏,王柳江,等.真空预压联合电渗法加固软基的固结方程[J].河海大学学报:自然科学版,2011,39(2):169-175.(XUWei,LIU Sihong,WANG Liujiang,et al.Analytical theory of soft ground consolidation under vacuum preloading combined with electro-osmosis[J].Journal of Hohai University:Natural Science,2011,39(2):169-175.(in Chinese))
[10]吴辉,胡黎明.真空预压与电渗固结联合加固技术的理论模型[J].清华大学学报:自然科学版,2012,52(2):182-185.(WU Hui,HU Liming.Analytical models of the coupling of vacuum preloading and electro-osmosis consolidation for ground stabilization[J].Journal of Tsinghua University:Natural Science,2012,52(2):182-185.(in Chinese))
[11]李剑,张仪萍,严露.真空-电渗联合作用下的软基固结计算研究[J].水运工程,2012,(3):133-138.(LI Jian,ZHANG Yiping,YAN Lu.Solutions for consolidation of soft ground under vacuum preloading combined with electro-osmosis[J].Port and Waterway Engineering,2012,(3):133-138.(in Chinese))
[12]WU H,HU L.Analytical solution for axisymmetric electro-osmotic consolidation[J].Géotechnique,2013,63(12):1 074-1 079.
[13]李瑛,龚晓南,张雪婵.电压对一维电渗排水影响的试验研究[J].岩土力学,2011,32(3):709-714.(LI Ying,GONG Xiaonan,ZHANGXuechan.Experimental research on effect of applied voltage on one-dimensional electroosmotic drainage[J].Rock and Soil Mechanics,2011,32(3):709-714.(in Chinese))
[14]龚明星,王档良,詹贵贵.考虑有效电势变化的软土一维电渗固结理论[J].水文地质工程地质,2015,42(4):61-66.(GONGMingxing,WANG Dangliang,ZHAN Guigui.1-D electro-osmotic consolidation theory considering variation in effective potential in soft soil[J].Hydrogeology and Engineering Geology,2015,42(4):61-66.(in Chinese))
[15]郭彪,龚晓南,卢萌盟,等.真空联合堆载预压下竖井地基固结解析解[J].岩土工程学报,2013,35(6):1 045-1 054.(GUO Biao,GONG Xiaonan,LU Mengmeng,et al.Analytical solution for consolidation of vertical drains by vacuum-surcharge preloading[J].Chinese Journal of Geotechnical Engineering,2013,35(6):1 045-1 054.(in Chinese))
[16]王柳江,刘斯宏,汪俊波,等.电场-渗流场-应力场耦合的电渗固结数值分析[J].岩土力学,2012,33(6):1 904-1 911.(WANGLiujiang,LIU Sihong,WANG Junbo,et al.Numerical analysis of electroosmostic consolidation based on coupled electrical field-seepage field-stress field[J].Rock and Soil Mechanics,2012,33(6):1 904-1 911.(in Chinese))
[2]房营光,徐敏,朱忠伟.碱渣土的真空-电渗联合排水固结特性试验研究[J].华南理工大学学报:自然科学版,2006,34(11):70-75.(FANG Yingguang,XU Min,ZHU Zhongwei.Experimental investigation into draining consolidation behavior of soda residue soil under vacuum preloading-electro-osmosis[J].Journal of South China University of Technology:Natural Science,2006,34(11):70-75.(in Chinese))
[3]王柳江,刘斯宏,汪俊波,等.真空预压联合电渗法处理高含水率软土模型试验[J].河海大学学报:自然科学版,2011,39(6):671-675.(WANG Liujiang,LIU Sihong,WANG Junbo,et al.Model test for high-water-content soft soil treatment under vacuum preloading in combination with electroosmosis[J].Journal of Hohai University:Natural Science,2011,39(6):671-675.(in Chinese))
[4]王军,张乐,刘飞禹,等.真空预压-电渗法联合加固软黏土地基试验研究[J].岩石力学与工程学报,2014,33(增2):4 181-4 192.(WANG Jun,ZHANG Le,LIU Feiyu,et al.Experimental study of vacuum preloading combined reinforcement with electro-osmosis in soft clay ground[J].Chinese Journal of Rock Mechanics and Engineering,2014,33(Supp.2):4 181-4 192.(in Chinese))
[5]WANG J,MA J,LIU F,et al.Experimental study on the improvement of marine clay slurry by electroosmosis-vacuum preloading[J].Geotextiles and Geomembranes,2016,44(4):615-622.
[6]孙召花,余湘娟,高明军,等.真空-电渗联合加固技术的固结试验研究[J].岩土工程学报,2017,39(2):250-258.(SUN Zhaohua,YU Xiangjuan,GAO Mingjun,et al.Experimental studies on vacuum preloading incorporated with electro-osmosis consolidation for dredger fill[J].Chinese Journal of Geotechnical Engineering,2017,39(2):250-258.(in Chinese))
[7]PENG J,XIONG X,MAHFOUZ A H,et al.Vacuum preloading combined electroosmotic strengthening of ultra-soft soil[J].Journal of Central South University,2013,20(11):3 282-3 295.
[8]鲍树峰,娄炎,董志良,等.新近吹填淤泥地基真空固结失效原因分析及对策[J].岩土工程学报,2014,36(7):1 350-1 359.(BAOShufeng,LOU Yan,DONG Zhiliang,et al.Causes and countermeasures for vacuum consolidation failure of newly-dredged mud foundation[J].Chinese Journal of Geotechnical Engineering,2014,36(7):1 350-1 359.(in Chinese))
[9]徐伟,刘斯宏,王柳江,等.真空预压联合电渗法加固软基的固结方程[J].河海大学学报:自然科学版,2011,39(2):169-175.(XUWei,LIU Sihong,WANG Liujiang,et al.Analytical theory of soft ground consolidation under vacuum preloading combined with electro-osmosis[J].Journal of Hohai University:Natural Science,2011,39(2):169-175.(in Chinese))
[10]吴辉,胡黎明.真空预压与电渗固结联合加固技术的理论模型[J].清华大学学报:自然科学版,2012,52(2):182-185.(WU Hui,HU Liming.Analytical models of the coupling of vacuum preloading and electro-osmosis consolidation for ground stabilization[J].Journal of Tsinghua University:Natural Science,2012,52(2):182-185.(in Chinese))
[11]李剑,张仪萍,严露.真空-电渗联合作用下的软基固结计算研究[J].水运工程,2012,(3):133-138.(LI Jian,ZHANG Yiping,YAN Lu.Solutions for consolidation of soft ground under vacuum preloading combined with electro-osmosis[J].Port and Waterway Engineering,2012,(3):133-138.(in Chinese))
[12]WU H,HU L.Analytical solution for axisymmetric electro-osmotic consolidation[J].Géotechnique,2013,63(12):1 074-1 079.
[13]李瑛,龚晓南,张雪婵.电压对一维电渗排水影响的试验研究[J].岩土力学,2011,32(3):709-714.(LI Ying,GONG Xiaonan,ZHANGXuechan.Experimental research on effect of applied voltage on one-dimensional electroosmotic drainage[J].Rock and Soil Mechanics,2011,32(3):709-714.(in Chinese))
[14]龚明星,王档良,詹贵贵.考虑有效电势变化的软土一维电渗固结理论[J].水文地质工程地质,2015,42(4):61-66.(GONGMingxing,WANG Dangliang,ZHAN Guigui.1-D electro-osmotic consolidation theory considering variation in effective potential in soft soil[J].Hydrogeology and Engineering Geology,2015,42(4):61-66.(in Chinese))
[15]郭彪,龚晓南,卢萌盟,等.真空联合堆载预压下竖井地基固结解析解[J].岩土工程学报,2013,35(6):1 045-1 054.(GUO Biao,GONG Xiaonan,LU Mengmeng,et al.Analytical solution for consolidation of vertical drains by vacuum-surcharge preloading[J].Chinese Journal of Geotechnical Engineering,2013,35(6):1 045-1 054.(in Chinese))
[16]王柳江,刘斯宏,汪俊波,等.电场-渗流场-应力场耦合的电渗固结数值分析[J].岩土力学,2012,33(6):1 904-1 911.(WANGLiujiang,LIU Sihong,WANG Junbo,et al.Numerical analysis of electroosmostic consolidation based on coupled electrical field-seepage field-stress field[J].Rock and Soil Mechanics,2012,33(6):1 904-1 911.(in Chinese))