›› 2015, Vol. 36 ›› Issue (S1): 573-576.doi: 10.16285/j.rsm.2015.S1.100

• Geotechnical Engineering • Previous Articles     Next Articles

Research on change law of hole diameter over time and space in drilling cast-in-place piles considering unloading effect

ZHAO Chun-feng1, 2, CHEN Hong-xiang1, 2, ZHAO Cheng1, 2, XUE Jin-xian3   

  1. 1. Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Tongji University, Shanghai 200092, China; 2. Department of Geotechnical Engineering, Tongji University, Shanghai 200092, China; 3. Shenzhen Expressway Engineering Consulting Co., Ltd., Shenzhen, Guangdong 518000, China
  • Received:2015-03-07 Online:2015-07-11 Published:2018-06-14

PDF (Chinese)

994

Abstract: Hole check-up is conducted on the construction of drilling cast-in-place piles in a practical engineering of Shanghai. Firstly, the changing law of hole diameter over time and space is summarized by analyzing the data of hole diameter considering unloading effect. The diameter reduction and time have positive correlation, and the reduction range is decreased gradually over time, until the hole diameter is stable. Variable quantity of hole diameter is disparate in different soil layers. The smaller the cohesion c is and the bigger the internal friction angle φ is, the poorer the stability of hole wall will be and the larger the variable quantity of hole diameter is. Secondly, a scientific and reasonable fitting formula is applied to fit the change of hole diameter over time in different soil layers; it is shown that the formula is of high degree of fitting and can truthfully reflect the changing law of hole diameter. At last, based on the Kelvin model, a changing formula of hole diameter is deduced by utilizing elastic theories and combining the fitting formula to explain the case more exactly. And another formula which is concerned with the stability of hole wall is also deduced to explain the different stabilities of different soil layers more reasonably. Some conclusions from this paper are of great reference value in the construction of hole-forming in drilling cast-in-place piles in Shanghai area.

Key words: unloading, hole diameter, fitting formula, changing formula of hole diameter, stability of hole wall

CLC Number: 

  • TU 473
[1] REN Qing-yang, ZHANG Huang-mei, LIU Jia-shen, . Rheological properties of mudstone under two unloading paths in experiments [J]. Rock and Soil Mechanics, 2019, 40(S1): 127-134.
[2] ZHAI Ming-lei, GUO Bao-hua, WANG Chen-lin, JIAO Feng, . Compression-shear failure characteristics of rock with penetrated fracture under normal unloading condition [J]. Rock and Soil Mechanics, 2019, 40(S1): 217-223.
[3] JIN Ai-bing, LIU Jia-we, ZHAO Yi-qing, WANG Ben-xin, SUN Hao, WEI Yu-dong, . Mechanical characteristics analysis of granite under unloading conditions [J]. Rock and Soil Mechanics, 2019, 40(S1): 459-467.
[4] WANG Chuan-ying, WANG Yi-teng, HAN Zeng-qiang, WANG Jin-chao, ZOU Xian-jian, HU Sheng, . An in-situ stress measurement method based on borehole shape analysis [J]. Rock and Soil Mechanics, 2019, 40(S1): 549-556.
[5] HOU Gong-yu, JING Hao-yong, LIANG Jin-ping, ZHANG Guang-dong, TAN Jin-xin, ZHANG Yong-kang, YANG Xi, . Experimental study of deformation and acoustic emission characteristics of rectangular roadway under different unloading rates [J]. Rock and Soil Mechanics, 2019, 40(9): 3309-3318.
[6] LI Jing-jing, KONG Ling-wei, . Creep properties of expansive soil under unloading stress and its nonlinear constitutive model [J]. Rock and Soil Mechanics, 2019, 40(9): 3465-3475.
[7] CHEN Yong, SU Jian, TAN Yun-zhi, CHAN Dave, . Water retention capacities of soils under the coupling actions of cyclic drying-wetting and repeated loading-unloading [J]. Rock and Soil Mechanics, 2019, 40(8): 2907-2913.
[8] LI Xin-ming, KONG Ling-wei, GUO Ai-guo, . Experimental study of ageing effect on mechanical properties of Nanyang undisturbed expansive soil [J]. Rock and Soil Mechanics, 2019, 40(8): 2947-2955.
[9] MA De-peng, ZHOU Yan, LIU Chuan-xiao, SHANG Yan-dong, . Energy evolution characteristics of coal failure in triaxial tests under different unloading confining pressure rates [J]. Rock and Soil Mechanics, 2019, 40(7): 2645-2652.
[10] LI Jian-peng, GAO Ling, MU Huan-sheng. Dilatancy characteristics of sandstone and its function of dilatancy angle under high confining pressure and unloading conditions [J]. Rock and Soil Mechanics, 2019, 40(6): 2119-2126.
[11] WANG Chen-lin, ZHANG Xiao-dong, DU Zhi-gang, . Experimental study of the permeability of coal specimen with pre-existing fissure under cyclic loading and unloading [J]. Rock and Soil Mechanics, 2019, 40(6): 2140-2153.
[12] WANG Tie-hang, JIN Xin, LUO Yang, ZHANG Song-lin. A method for evaluation of loess collapse potential of unloading [J]. Rock and Soil Mechanics, 2019, 40(4): 1281-1290.
[13] CONG Yi, CONG Yu, ZHANG Li-ming, JIA Le-xin, WANG Zai-quan, . 3D particle flow simulation of loading-unloading failure process of marble [J]. Rock and Soil Mechanics, 2019, 40(3): 1179-1186.
[14] HOU Gong-yu, LIANG Jin-ping, JING Hao-yong, HU Tao, ZHANG Guang-dong, TAN Jin-xin, YANG Xi, ZHANG Yong-kang, . Acoustic emission characteristics of thick-walled cylinder specimen subjected to triaxial loading during excavation unloading [J]. Rock and Soil Mechanics, 2019, 40(12): 4564-4572.
[15] LI Xin-ming, KONG Ling-wei, GUO Ai-guo, . Experimental study on shear mechanical properties of unloading damaged undisturbed expansive soil [J]. Rock and Soil Mechanics, 2019, 40(12): 4685-4692.
Viewed
Full text


Abstract

Cited
  Shared   
  Discussed   
[1] ZHANG Wen-jie，CHEN Yum-min. Pumping tests and leachate drawdown design in a municipal solid waste landfill[J]. , 2010, 31(1): 211 -215 .
[2] GONG Wei-li, AN Li-qian, ZHAO Hai-yan, MAO Ling-tao. Multiple scale characterization of CT image for coal rock fractures based on image description[J]. , 2010, 31(2): 371 -376 .
[3] WAN Zhi, DONG Hui, LIU Bao-chen. On choice of hyper-parameters of support vector machines for time series regression and prediction with orthogonal design[J]. , 2010, 31(2): 503 -508 .
[4] SUN Xi-yuan, LUAN Mao-tian, TANG Xiao-wei. Study of horizontal bearing capacity of bucket foundation on saturated soft clay ground[J]. , 2010, 31(2): 667 -672 .
[5] WANG Ming-nian, GUO Jun, LUO Lu-sen, Yu Yu, Yang Jian-min, Tan Zhon. Study of critical buried depth of large cross-section loess tunnel for high speed railway[J]. , 2010, 31(4): 1157 -1162 .
[6] HU Yong-gang, LUO Qiang, ZHANG Liang, HUANG Jing, CHEN Ya-mei. Deformation characteristics analysis of slope soft soil foundation treatment with mixed-in-place pile by centrifugal model tests[J]. , 2010, 31(7): 2207 -2213 .
[7] TAN Feng-yi, Jiang Zhi-quan, Li Zhong-qiu, YAN Hui-he. Application of additive mass method to testing compacted density of filling material in Kunming new airport[J]. , 2010, 31(7): 2214 -2218 .
[8] CHAI Bo, YIN Kun-long, XIAO Yong-jun. Characteristics of weak-soft zones of Three Gorges Reservoir shoreline slope in new Badong county[J]. , 2010, 31(8): 2501 -2506 .
[9] WANG Guang-jin，YANG Chun-he ，ZHANG Chao，MA Hong-ling，KONG Xiang-yun ，HO. Research on particle size grading and slope stability analysis of super-high dumping site[J]. , 2011, 32(3): 905 -913 .
[10] HU Hai-jun, JIANG Ming-jing, ZHAO Tao, PENG Jian-bing, LI Hong. Effects of specimen-preparing methods on tensile strength of remolded loess[J]. , 2009, 30(S2): 196 -199 .
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