›› 2014, Vol. 35 ›› Issue (S2): 600-606.

• Numerical Analysis • Previous Articles     Next Articles

Mechanism and numerical analysis of effect of air injection on vacuum preloading for weak foundation improvement

TU Hong-zhen1，XU Yan-hui2，XIE Li-quan2   

  1. 1. Port and Shipping Management Bureau of Wenzhou, Wenzhou, Zhejiang 325088, China; 2. College of Civil Engineering, Tongji University, Shanghai 200092, China
  • Received:2014-05-15 Online:2014-10-31 Published:2014-11-12

PDF (Chinese)

978

Abstract: Vacuum preloading technique without sand cushion layer has been successfully applied to the weak foundation reinforcement; but it is difficult to shorten construction period due to the low permeability of weak soil. Intermittent air injection is proposed to increase the drainage rate for vacuum drainage. The combined method of vacuum preloading and air injection is investigated for different conditions of the injecting positions and air pressures based on finite element simulation. Seepage velocity, drainage rate and seepage gradient are compared and analyzed before and after air injection. The simulation results show that the air injection can improve the efficiency of vacuum drainage, so as to enhance the foundation reinforcement and reduce preloading time of the vacuum loading. The efficiency of injecting air below the drain boards is better than that above the bottom ends of boards. And in the case of not breaking through the foundation in the air injection, the greater the air pressure is set, the better effect of reinforcement will be. The combined method of vacuum preloading and air injection could be widely used in the improvement practice of weak ground.

Key words: vacuum preloading, construction period, intermittent air injection, weak foundation improvement

CLC Number: 

  • TU 755.6+2
[1] SHI Li, HU Dong-dong, CAI Yuan-qiang, PAN Xiao-dong, SUN Hong-lei, . Preliminary study of real-time pore water pressure response and reinforcement mechanism of air-booster vacuum preloading treated dredged slurry [J]. Rock and Soil Mechanics, 2020, 41(1): 185-193.
[2] LEI Hua-yang, HU Yao, LEI Shuang-hua, QI Zi-yang, XU Ying-gang, . Analysis of microstructure characteristics of air-booster vacuum preloading for ultra-soft dredger fills [J]. Rock and Soil Mechanics, 2019, 40(S1): 32-40.
[3] ZHANG Yu-guo, WAN Dong-yang, ZHENG Yan-lin, HAN Shuai, YANG Han-yue, DUAN Meng-meng. Analytical solution for consolidation of vertical drain under vacuum preloading considering the variation of radial permeability coefficient [J]. Rock and Soil Mechanics, 2019, 40(9): 3533-3541.
[4] DONG Zhi-hong, NIU Xin-qiang, DING Xiu-li, WENG YongHong, HUANG Shu-ling, PEI Qi-tao, ZHANG Lian, . Deformation characteristics and feedback analysis of surrounding rock of underground powerhouse at left bank of Wudongde Hydropower Station [J]. Rock and Soil Mechanics, 2018, 39(S2): 326-336.
[5] LIU Xiao-ke, LU Qun, LU Shi-wei, LIU Chun-long, GUO Shao-long,. Vacuum penetration and ultimate pull-out capacity of low skirted suction caissons [J]. , 2018, 39(6): 2089-2098.
[6] HUANG Chao-xuan, WANG Zheng-zhong, FANG Yong-lai,. Analytical solution of vacuum preloading foundation considering air leakage and nonlinear well resistance [J]. , 2017, 38(9): 2574-2582.
[7] LIU Yong, QI Lan, LI Shao-ming, GUO Hao-yang,. 3D Finite element analysis of vacuum preloading considering inconstant well resistance and smearing effects [J]. , 2017, 38(5): 1517-1523.
[8] WU Ya-jun, NIU Kun, TANG Hai-feng, HU Zhi-gang, LU Yi-tian，. Enhanced permeability of calcium lime in construction waste slurry improvement by vacuum preloading with flocculation [J]. , 2017, 38(12): 3453-3461.
[9] BAO Shu-feng, LOU Yan, DONG Zhi-liang, NIU Fei, XIE Rong-xing, . Development of a new apparatus for measurement of groundwater level under vacuum pre-loading [J]. , 2017, 38(10): 3067-3073.
[10] FENG Fan, QIU Xin-jiao, ZHANG Guo-xin, GUAN Jun-feng, WANG Dan，. Inversion of mechanical parameters of super-high arch dam based on deformation monitoring during construction period [J]. , 2017, 38(1): 237-246.
[11] SHEN Yang , WANG Bao-guang , TAO Ming-an , WANG Xin , DU Wen-han，. Improvement of preparing technique for hollow cylinder specimen of remolded clay and its application [J]. , 2015, 36(S1): 697-701.
[12] BAO Shu-feng ，DONG Zhi-liang ，MO Hai-hong ，WU Dong-qing,. Laboratory tests on new reinforcement technology of newly hydraulic reclamation mud with high clay content [J]. , 2015, 36(1): 61-67.
[13] LE Chao , XU Chao , WU Xue-feng , JIN Ya-wei，. Experimental research on clogging characteristic of two types of PVD filters [J]. , 2014, 35(9): 2529-2534.
[14] BAO Shu-feng , MO Hai-hong , DONG Zhi-liang , CHEN Ping-shan , QIU Qing-chang,. Research on transfer properties and distribution model of negative pressure in fresh hydraulic reclamation muck foundation [J]. , 2014, 35(12): 3569-3576.
[15] ZHANG Fu-hai ，CHEN Lei ，GUO Shuai-jie ，REN Peng-xun , . Analytical solution for consolidation of sand-drained foundation with bottom vacuum preloading method [J]. , 2014, 35(10): 2787-2793.
Viewed
Full text


Abstract

Cited
  Shared   
  Discussed   
[1] GUAN Yun-fei，GAO Feng，ZHAO Wei-bing，YU Jin. Secondary development of modified Cambridge model in ANSYS software[J]. , 2010, 31(3): 976 -980 .
[2] MI Hai-zhen, GAO Chun. Experimental study of expansive behaviors of quicklime[J]. , 2010, 31(4): 1253 -1256 .
[3] SONG Fei，LIU Chao，ZHANG Jian-min，ZHENG Rui-hua. Development of centrifuge model test facility of retaining wall[J]. , 2010, 31(9): 3005 -3011 .
[4] SUN Xi-ping, ZHANG Bao-hua, ZHANG Qiang, WANG Xiao-nan. Stability analysis of gravity quay when rubble bedding was eroded by water flow[J]. , 2010, 31(10): 3184 -3190 .
[5] CHEN Jing-yu , GONG Xiao-nan, DENG Ya-hong. Research on dissipation of excess pore water pressure in one-dimensional finite strain consolidation of soft clays[J]. , 2009, 30(1): 191 -195 .
[6] SUN Jian , WANG Lian-guo , TANG Fu-rong , SHEN Yi-feng , GONG Shi-long. Microseismic monitoring failure characteristics of inclined coal seam floor[J]. , 2011, 32(5): 1589 -1595 .
[7] YANG Yong-xiang , ZHOU Jian , JIA Min-cai , HU Jin-hu. Visualization testing on liquefaction properties of saturated sands[J]. , 2011, 32(6): 1643 -1648 .
[8] XU Zheng-ming, XUE Qiang, ZHAO Ying. Research on time effect of modified sludge composites by triaxial tests on mechanical properties[J]. , 2011, 32(6): 1713 -1718 .
[9] CHEN Ming , HU Ying-guo , LU Wen-bo , YAN Peng , ZHOU Chuang-bing. Blasting excavation induced damage characteristics of diversion tunnel for Jinping cascade II hydropower station[J]. , 2011, 32(S2): 172 -177 .
[10] WANG Tao , LI Yang , ZHOU Yong , Lü Qing , LIU Da-wei. Research on safety specific report of phosphogypsum tailings ponds[J]. , 2011, 32(S2): 407 -412 .
Copyright © Rock and Soil Mechanics, All Rights Reserved.
Tel: 027-87198484, 87199252, 87199253, 87198752　E-mail: ytlx@whrsm.ac.cn
Powered by Beijing Magtech Co. Ltd