基于C-C型固化剂的吹填超软土渗透固结特性研究
|
摘要
在吹填超软土中加入不同掺量的C-C型固化剂进行压缩固结试验和真空固结试验,对固结前后土体的渗透固结特性和基于有效孔隙比与孔隙抗压性能的增渗机制进行研究,探究既能提高渗透性,又能保持较高强度的合理掺量.发现半固化超软土的固结特性与软黏土基本一致,固结系数随固结压力的增大而增大,渗透系数随荷载的增大而减小;相同荷载作用下,固结系数和渗透系数均随掺量的增加而增大.加入少量固化剂后,压汞试验显示孔径分布曲线峰值明显左移,孔径集中分布区间向小孔隙区间移动,土样有效孔隙比随掺量变化存在最大值,土体骨架的存在使得孔隙抗压缩性能不断增加,保留了具有较高强度结构的排水通道,这种压缩性较低的多孔骨架结构对渗透性的提高有着显著作用.固化过程中,固化剂掺量越多,形成土骨架的作用越明显,土体强度和抗压缩能力就越高,其中掺量为10%的土样无侧限抗压强度高达360.1kPa,远高于直接固化强度.研究表明,固化剂掺量在1%～10%时,主要发挥的是增渗作用,是药剂真空预压处理超软土的理想添加范围;而大于10%后以固化作用为主.
To determine the optimal dosage of C-C type curing agents in the hydraulic fill ultra-soft soil for both permeability and strength improvement,compression consolidation test and vacuum consolidation test were carried out.After the test,the mechanism of permeability and consolidation characteristics improvement was evaluated by the effective pore ratio and the pore anti-compressive performance.Test results show that the consolidation coefficient of the semi-solidification ultra-soft soil,similar with soft clay,is increased with increasing pressure while the permeability coefficient is decreased with increasing load.And the coefficients are increased with the increasing addition under the same load.After adding a small amount of curing agents,mercury injection test shows that the peak value of pore size distribution curve shifts to left evidently,interval of concentrated aperture is moved to small pore interval,and the effective pore ratio exists maximum with different additions.The porous structure with low compressibility,increasing compressive properties of pores,retaining high strength drainage path and improving permeability,is formed.The more the curing agent is added,the more obvious the phenomenon of soil skeleton is and the higher soil strength and anticompression ability are.Particularly,the unconfined compressive strength of the sample with 10%addition is up to 360.1kPa.It is far higher than that of the sample prepared by curing only.The study reveals that with the addition in 1%-10%,curing agents can improve the permeability primarily,and it is appropriate for vacuum preloading with flocculants treatment,and while>10%,curing action will be primary.
To determine the optimal dosage of C-C type curing agents in the hydraulic fill ultra-soft soil for both permeability and strength improvement,compression consolidation test and vacuum consolidation test were carried out.After the test,the mechanism of permeability and consolidation characteristics improvement was evaluated by the effective pore ratio and the pore anti-compressive performance.Test results show that the consolidation coefficient of the semi-solidification ultra-soft soil,similar with soft clay,is increased with increasing pressure while the permeability coefficient is decreased with increasing load.And the coefficients are increased with the increasing addition under the same load.After adding a small amount of curing agents,mercury injection test shows that the peak value of pore size distribution curve shifts to left evidently,interval of concentrated aperture is moved to small pore interval,and the effective pore ratio exists maximum with different additions.The porous structure with low compressibility,increasing compressive properties of pores,retaining high strength drainage path and improving permeability,is formed.The more the curing agent is added,the more obvious the phenomenon of soil skeleton is and the higher soil strength and anticompression ability are.Particularly,the unconfined compressive strength of the sample with 10%addition is up to 360.1kPa.It is far higher than that of the sample prepared by curing only.The study reveals that with the addition in 1%-10%,curing agents can improve the permeability primarily,and it is appropriate for vacuum preloading with flocculants treatment,and while>10%,curing action will be primary.
引文
[1] BO M W.Compressibility of Ultra-Soft Soil[M].Singapore:World Scientific,2008.
[2] CHAI J C,CARTER J P,HAYASHI S.Ground deformation induced by vacuum consolidation[J].Journal of Geotechnical and Geoenvironmental Engineering,ASCE,2005,131(12):1552-1561.
[3] CHAIJinchun, HONGZhenshun, SHEN Shuilong. Vacuum-drainconsolidationinduced pressure distribution and ground deformation[J].Geotextiles and Geomembranes,2010,28(6):525-535.
[4] BO M W,CHOA V,WONG K S.Constant rate of loading test on ultra-soft soil[J].Geotechnical Testing Journal,2010,33(3):192-200.
[5] HARVEY J A F.Vacuum drainage to accelerate submarine consolidation at Chek Lap Kok,Hong Kong[J].Ground Engineering,1997,30(6):34-36.
[6] SAOWAPAKPIBOONJ, BERGADODT,YOUWAI S,et al. Measured and predicted performance of prefabricated vertical drains(PVDs)with and without vacuum preloading[J].Geotextiles and Geomembranes,2010,28(1):1-11.
[7]高志义.真空预压法的机理分析[J].岩土工程学报,1989,11(4):45-56.GAO Zhiyi. Analysis on mechanics of vacuum preloading method[J]. Chinese Journal of Geotechnical Engineering,1989,11(4):45-56.(in Chinese)
[8] BO M W,CHOA V,WONG K S.Reclamation and soil improvement on ultra-soft soil[J].Ground Improvement,2005,9(1):23-31.
[9]董志良,张功新,周琦,等.天津滨海新区吹填造陆浅层超软土加固技术研发及应用[J].岩石力学与工程学报,2011,30(5):1073-1080.DONG Zhiliang,ZHANG Gongxin,ZHOU Qi,et al.Research and application of improvement technology of shallow ultra-soft soil formed by hydraulic reclamation in Tianjin Binhai New Area[J].Chinese Journal of Rock Mechanics and Engineering,2011,30(5):1073-1080.(in Chinese)
[10]曹永华,李卫,刘天韵.浅层超软土地基真空预压加固技术[J].岩土工程学报,2011,33(S1):234-238.CAO Yonghua,LI Wei,LIU Tianyun.Surfacelayer improvement technology for ultra soft soil by vacuum preloading[J]. Chinese Journal of Geotechnical Engineering,2011,33(S1):234-238.(in Chinese)
[11]武亚军,陆逸天,牛坤,等.一种处理工程废浆的药剂真空预压法:ZL 2015 1 0322445.6[P].2017-09-29.WU Yajun,LU Yitian,NIU Kun,et al.A vacuum preloading with flocculation for treating engineering waste mud:ZL 2015 1 0322445.6[P].2017-09-29.(in Chinese)
[12]WU Yajun,KONG Gangqiang,LU Yitian,et al.Experimental study on vacuum preloading with flocculation in waste slurry improvement[J].Geomechanics and Engineering,2017,13(2):319-331.
[13]武亚军,陆逸天,牛坤,等.药剂真空预压法处理工程废浆试验[J].岩土工程学报,2016,38(8):1365-1373.WU Yajun, LU Yitian, NIU Kun, et al.Experimental study on solid-liquid separation of construction waste slurry by additive agentcombined vacuum preloading[J].Chinese Journal of Geotechnical Engineering,2016,38(8):1365-1373.(in Chinese)
[14]武亚军,陆逸天,骆嘉成,等.药剂真空预压法在工程废浆处理中的防淤堵作用[J].岩土工程学报,2017,39(3):525-533.WU Yajun,LU Yitian,LUO Jiacheng,et al.Anticlogging function of vacuum preloading with flocculants in solid-liquid separation of construction waste slurry[J].Chinese Journal of Geotechnical Engineering,2017,39(3):525-533.(in Chinese)
[15]武亚军,牛坤,陆逸天,等.工程废浆处理过程中药剂真空预压法的防淤堵机理[J].土木工程学报,2017,50(6):95-103.WU Yajun,NIU Kun,LU Yitian,et al.Anticlogging mechanism of vacuum preloading with flocculationintreatingconstructionwaste slurry[J].China Civil Engineering Journal,2017,50(6):95-103.(in Chinese)
[16]武亚军,杨建波,张孟喜.真空加载方式对吹填流泥加固效果及土颗粒移动的影响研究[J].岩土力学,2013,34(8):2129-2135.WU Yajun, YANG Jianbo, ZHANG Mengxi.Study of impact of vacuum loading mode on dredger fill flow mud consolidation effect and soil particles moving[J]. Rock and Soil Mechanics,2013,34(8):2129-2135.(in Chinese)
[17]朱耀庭,郑爱荣,李卫.吹填超软土固结特性的试验研究[J].湖南大学学报(自然科学版),2008,35(11):120-123.ZHUYaoting, ZHENGAirong, LIWei.Laboratory tests for the consolidation property of dredger fill in the Shenzhen area[J].Journal of Hunan University(Nature Sciences),2008,35(11):120-123.(in Chinese)
[18]文海家,李耀刚,汪东云.超软土渗透固结的控制性因素分析[J].重庆建筑大学学报,2000,22(z1):9-14.WEN Haijia, LI Yaogang, WANG Dongyun.Analysis on governing factors of seepage and consolidation of super soft soil[J].Journal of Chongqing Jianzhu University,2000,22(z1):9-14.(in Chinese)
[19]BO M W,CHOA V,WONG K S.Compression test on slurry with small scale consolidation[J].Canadian Geotechnical Journal,2002,39:388-398.
[20]党发宁,刘海伟,王学武,等.基于有效孔隙比的黏性土渗透系数经验公式研究[J].岩石力学与工程学报,2015,34(9):1909-1917.DANG Faning, LIU Haiwei, WANG Xuewu,et al.Empirical formulas of permeability of clay based on effective pore ratio[J].Chinese Journal of Rock Mechanics and Engineering,2015,34(9):1909-1917.(in Chinese)
[21]SHEAR D L,OLSEN H W,NELSON K R.Effects of Desiccation on the Hydraulic Conductivity Versus Void Ratio Relationship for a Natural Clay[M]. Washington D C:National Academy Press,1992.
[2] CHAI J C,CARTER J P,HAYASHI S.Ground deformation induced by vacuum consolidation[J].Journal of Geotechnical and Geoenvironmental Engineering,ASCE,2005,131(12):1552-1561.
[3] CHAIJinchun, HONGZhenshun, SHEN Shuilong. Vacuum-drainconsolidationinduced pressure distribution and ground deformation[J].Geotextiles and Geomembranes,2010,28(6):525-535.
[4] BO M W,CHOA V,WONG K S.Constant rate of loading test on ultra-soft soil[J].Geotechnical Testing Journal,2010,33(3):192-200.
[5] HARVEY J A F.Vacuum drainage to accelerate submarine consolidation at Chek Lap Kok,Hong Kong[J].Ground Engineering,1997,30(6):34-36.
[6] SAOWAPAKPIBOONJ, BERGADODT,YOUWAI S,et al. Measured and predicted performance of prefabricated vertical drains(PVDs)with and without vacuum preloading[J].Geotextiles and Geomembranes,2010,28(1):1-11.
[7]高志义.真空预压法的机理分析[J].岩土工程学报,1989,11(4):45-56.GAO Zhiyi. Analysis on mechanics of vacuum preloading method[J]. Chinese Journal of Geotechnical Engineering,1989,11(4):45-56.(in Chinese)
[8] BO M W,CHOA V,WONG K S.Reclamation and soil improvement on ultra-soft soil[J].Ground Improvement,2005,9(1):23-31.
[9]董志良,张功新,周琦,等.天津滨海新区吹填造陆浅层超软土加固技术研发及应用[J].岩石力学与工程学报,2011,30(5):1073-1080.DONG Zhiliang,ZHANG Gongxin,ZHOU Qi,et al.Research and application of improvement technology of shallow ultra-soft soil formed by hydraulic reclamation in Tianjin Binhai New Area[J].Chinese Journal of Rock Mechanics and Engineering,2011,30(5):1073-1080.(in Chinese)
[10]曹永华,李卫,刘天韵.浅层超软土地基真空预压加固技术[J].岩土工程学报,2011,33(S1):234-238.CAO Yonghua,LI Wei,LIU Tianyun.Surfacelayer improvement technology for ultra soft soil by vacuum preloading[J]. Chinese Journal of Geotechnical Engineering,2011,33(S1):234-238.(in Chinese)
[11]武亚军,陆逸天,牛坤,等.一种处理工程废浆的药剂真空预压法:ZL 2015 1 0322445.6[P].2017-09-29.WU Yajun,LU Yitian,NIU Kun,et al.A vacuum preloading with flocculation for treating engineering waste mud:ZL 2015 1 0322445.6[P].2017-09-29.(in Chinese)
[12]WU Yajun,KONG Gangqiang,LU Yitian,et al.Experimental study on vacuum preloading with flocculation in waste slurry improvement[J].Geomechanics and Engineering,2017,13(2):319-331.
[13]武亚军,陆逸天,牛坤,等.药剂真空预压法处理工程废浆试验[J].岩土工程学报,2016,38(8):1365-1373.WU Yajun, LU Yitian, NIU Kun, et al.Experimental study on solid-liquid separation of construction waste slurry by additive agentcombined vacuum preloading[J].Chinese Journal of Geotechnical Engineering,2016,38(8):1365-1373.(in Chinese)
[14]武亚军,陆逸天,骆嘉成,等.药剂真空预压法在工程废浆处理中的防淤堵作用[J].岩土工程学报,2017,39(3):525-533.WU Yajun,LU Yitian,LUO Jiacheng,et al.Anticlogging function of vacuum preloading with flocculants in solid-liquid separation of construction waste slurry[J].Chinese Journal of Geotechnical Engineering,2017,39(3):525-533.(in Chinese)
[15]武亚军,牛坤,陆逸天,等.工程废浆处理过程中药剂真空预压法的防淤堵机理[J].土木工程学报,2017,50(6):95-103.WU Yajun,NIU Kun,LU Yitian,et al.Anticlogging mechanism of vacuum preloading with flocculationintreatingconstructionwaste slurry[J].China Civil Engineering Journal,2017,50(6):95-103.(in Chinese)
[16]武亚军,杨建波,张孟喜.真空加载方式对吹填流泥加固效果及土颗粒移动的影响研究[J].岩土力学,2013,34(8):2129-2135.WU Yajun, YANG Jianbo, ZHANG Mengxi.Study of impact of vacuum loading mode on dredger fill flow mud consolidation effect and soil particles moving[J]. Rock and Soil Mechanics,2013,34(8):2129-2135.(in Chinese)
[17]朱耀庭,郑爱荣,李卫.吹填超软土固结特性的试验研究[J].湖南大学学报(自然科学版),2008,35(11):120-123.ZHUYaoting, ZHENGAirong, LIWei.Laboratory tests for the consolidation property of dredger fill in the Shenzhen area[J].Journal of Hunan University(Nature Sciences),2008,35(11):120-123.(in Chinese)
[18]文海家,李耀刚,汪东云.超软土渗透固结的控制性因素分析[J].重庆建筑大学学报,2000,22(z1):9-14.WEN Haijia, LI Yaogang, WANG Dongyun.Analysis on governing factors of seepage and consolidation of super soft soil[J].Journal of Chongqing Jianzhu University,2000,22(z1):9-14.(in Chinese)
[19]BO M W,CHOA V,WONG K S.Compression test on slurry with small scale consolidation[J].Canadian Geotechnical Journal,2002,39:388-398.
[20]党发宁,刘海伟,王学武,等.基于有效孔隙比的黏性土渗透系数经验公式研究[J].岩石力学与工程学报,2015,34(9):1909-1917.DANG Faning, LIU Haiwei, WANG Xuewu,et al.Empirical formulas of permeability of clay based on effective pore ratio[J].Chinese Journal of Rock Mechanics and Engineering,2015,34(9):1909-1917.(in Chinese)
[21]SHEAR D L,OLSEN H W,NELSON K R.Effects of Desiccation on the Hydraulic Conductivity Versus Void Ratio Relationship for a Natural Clay[M]. Washington D C:National Academy Press,1992.