Stability Analysis and Support Suggestions of Pile Hole Based on Mud Pressure Balance Earth Pressure

doi:10.16183/j.cnki.jsjtu.2018.330

Abstract

Abstract:

Based on the principle of mud pressure balance earth pressure, this paper establishes a mechanical model for analyzing the stability of pile hole, and analyzes the applicable conditions and application scopes of the three construction methods, namely, no-support excavation, the hole formation method by mud retaining wall, and the hole formation method by hard support. It also provides reasonable determination methods for maximum depth of pore-creating without support, lower limit value of mud weight of protecting wall, and useful tables. The research results show that the friction angle, the cohesion, and the mud weight of soil are basic factors for maintaining the stability of the pile hole. When the depth of pore-forming is less than the maximum depth of pore-creating without support, no-support excavation can be adopted. Otherwise, hole-forming should be assisted by slurry-support, and mud weight should not be less than the lower limit value of mud weight for the retaining wall determined by the site soil. When the friction angle is greater than 25°, mud weight can be arbitrarily selected. When the lower limit value of mud weight for the retaining wall calculated by look-up table is greater than the maximum mud weight given by specification, casing or other hard support measures should be adopted.

Key words: stability of pile hole, mud of protecting wall, mud weight, critical depth without support

CLC Number:

TU441.35

XIONG Guojun, WANG Jianhua, CHEN Jinjian. Stability Analysis and Support Suggestions of Pile Hole Based on Mud Pressure Balance Earth Pressure[J]. Journal of Shanghai Jiao Tong University, 2021, 55(9): 1108-1115.

Figures/Tables 9

Fig.1

Tab.1

Fig.2

Fig.3

Tab.2

$\bar{z}_{cr}$ at different friction angles and relative cohesions

φ/ (°)	$z - cr$
φ/ (°)	c/(γR_A) =1	c/(γR_A) =2	c/(γR_A) =3	c/(γR_A) =4	c/(γR_A) =5	c/(γR_A) =6	c/(γR_A) =7	c/(γR_A) =8	c/(γR_A) =9	c/(γR_A) =10	c/(γR_A) =11	c/(γR_A) =12	c/(γR_A) =13	c/(γR_A) =14	c/(γR_A) =15
0	2.3	4.5	6.6	8.6	10.6	12.5	14.4	16.3	18.2	20.0	21.8	23.6	25.4	27.2	29.0
5	2.7	5.2	7.9	10.1	12.5	14.8	17.1	20.5	21.7	24.0	26.1	28.3	30.5	32.7	34.9
10	3.0	6.2	9.3	12.3	15.3	18.3	21.3	24.0	27.1	30.0	32.9	35.8	38.6	41.5	44.3
15	3.6	7.6	11.7	15.9	20.0	24.2	28.3	32.7	36.5	40.5	44.7	48.7	52.8	56.8	60.9
20	4.5	10.2	16.3	22.6	29.0	35.5	41.9	48.4	54.9	61.4	68.0	74.5	81.0	87.5	94.0
25	6.1	15.5	26.1	37.3	50.1	62.2	74.5	86.8	99.2	111.5	124.1	136.7	149.3	161.9	174.6
30	10.8	31.7	60.2	78.4	120.2	150.9	180.8	214.9	226.7	281.3	316.1	350.6	377.0	415.7	456.1
35	35.8	140.6	263.5	382.7	495.7	603.7	725.1	1036.9	1189.2	1341.7	∞	∞	∞	∞	∞
40	580.8	∞	∞	∞	∞	∞	∞	∞	∞	∞	∞	∞	∞	∞	∞

Tab.2

Fig.4

Tab.3

γ - sw _ min at different friction angles and relative cohesions

φ/(°)	$γ - sw_min$
φ/(°)	c/(γR_A) =1	c/(γR_A) =2	c/(γR_A) =3	c/(γR_A) =4	c/(γR_A) =5	c/(γR_A) =6	c/(γR_A) =7	c/(γR_A) =8	c/(γR_A) =9	c/(γR_A) =10	c/(γR_A) =11	c/(γR_A) =12	c/(γR_A) =13	c/(γR_A) =14	c/(γR_A) =15
0	—	—	—	—	—	—	—	—	—	—	—	—	—	—	—
5	0.804	0.826	0.848	0.870	0.892	0.914	0.936	0.958	0.980	1.002	1.024	1.046	1.068	1.091	1.113
10	0.606	0.623	0.641	0.658	0.675	0.692	0.709	0.726	0.744	0.761	0.778	0.795	0.812	0.829	0.847
15	0.438	0.451	0.464	0.477	0.490	0.504	0.517	0.530	0.543	0.556	0.569	0.583	0.596	0.609	0.622
20	0.279	0.289	0.299	0.309	0.319	0.329	0.338	0.348	0.358	0.368	0.378	0.388	0.397	0.407	0.417
25	0.188	0.195	0.202	0.209	0.216	0.223	0.230	0.237	0.244	0.251	0.258	0.265	0.272	0.279	0.286
30	0.106	0.111	0.115	0.12	0.124	0.129	0.134	0.138	0.143	0.147	0.152	0.156	0.161	0.166	0.170
35	0.050	0.053	0.056	0.058	0.061	0.064	0.066	0.069	0.071	0.074	0.077	0.079	0.082	0.085	0.087

Tab.3

Fig.5

Tab.4

$\bar{z}_{max}$ at different friction angles and relative cohesions

φ/(°)	$z - max$
φ/(°)	c/(γR_A)=1	c/(γR_A)=2	c/(γR_A)=3	c/(γR_A)=4	c/(γR_A)=5	c/(γR_A)=6	c/(γR_A)=7	c/(γR_A)=8
0	7.5	14.2	20.5	26.7	32.7	38.7	44.6	50.6
5	28.6	58.8	88.0	116.5	144.6	172.5	200.2	227.7
φ/(°)	$z - max$
φ/(°)	c/(γR_A)=9	c/(γR_A)=10	c/(γR_A)=11	c/(γR_A)=12	c/(γR_A)=13	c/(γR_A)=14	c/(γR_A)=15	c/(γR_A)=16
0	56.4	62.3	68.2	74.0	79.9	85.8	91.6	—
5	255.1	282.4	309.6	336.9	363.8	390.7	417.2	—

Tab.4

References 19

[1]	陈国灿. 钻孔灌注桩孔壁稳定的条件[J]. 长春工程学院学报(自然科学版), 2002, 3(3):36-39.
	CHEN Guocan. The conditions of keeping the hole-wall of pre-bored holes from yielding[J]. Journal of Changchun Institute of Technology (Nature Science Edition), 2002, 3(3):36-39.
[2]	胡晓敏, 李之达. 厚冲积覆盖层地区桥梁钻孔灌注桩成孔的力学分析[J]. 武汉理工大学学报(交通科学与工程版), 2007, 31(4):734-737.
	HU Xiaomin, LI Zhida. Hole forming mechanics analysis of the bored filling pile on the bridges in alluviation overburden area[J]. Journal of Wuhan University of Technology (Transportation Science & Engineering), 2007, 31(4):734-737.
[3]	王利群, 韩洪德, 许子峰. 人工挖孔桩桩孔稳定性分析[J]. 辽宁工程技术大学学报(自然科学版), 2002, 21(2):177-179.
	WANG Liqun, HAN Hongde, XU Zifeng. The piles holes stabilization analysis of hand-excavation holes piles[J]. Journal of Liaoning Technical University (Natural Science Edition), 2002, 21(2):177-179.
[4]	李小青, 郝行舟, 朱宏平, 等. 大口径钻孔灌注桩的孔壁稳定研究分析[J]. 华中科技大学学报(城市科学版), 2007, 24(2):25-28.
	LI Xiaoqing, HAO Xingzhou, ZHU Hongping, et al. Analysis on the stability of hole wall of large diameter bored pile[J]. Journal of Huazhong University of Science and Technology (Urban Science Edition), 2007, 24(2):25-28.
[5]	王云岗, 章光, 胡琦. 钻孔灌注桩孔壁稳定性分析[J]. 岩石力学与工程学报, 2011, 30(Sup.1):3281-3287.
	WANG Yungang, ZHANG Guang, HU Qi. Analysis of stability of bored pile hole-wall[J]. Chinese Journal of Rock Mechanics and Engineering, 2011, 30(Sup.1):3281-3287.
[6]	姚志伟. 厚砂层钻孔灌注桩泥浆护壁稳定性研究[D]. 武汉: 武汉理工大学, 2012.
	YAO Zhiwei. The stability of the slurry hole-wall of bored piles in thick sand[D]. Wuhan: Wuhan University of Technology, 2012.
[7]	王作成. 大直径污水井孔壁失稳与泥浆护壁机理[J]. 中南大学学报(自然科学版), 2012, 43(12):4859-4864.
	WANG Zuocheng. Hole wall instability and mechanism of slurry protection about large diameter bilge well[J]. Journal of Central South University (Science and Technology), 2012, 43(12):4859-4864.
[8]	黄博杰. 考虑圆拱效应与应力集中效应的桩孔自立稳定深度研究[D]. 重庆: 重庆大学, 2017.
	HUANG Bojie. Study on the independent stability depth of pile hole considering circular arch effect and stress concentration effect[D]. Chongqing: Chongqing University, 2017.
[9]	黄博杰, 曹永红, 华建民, 等. 考虑圆拱效应的桩孔最大自立深度[J]. 土木建筑与环境工程, 2018, 40(2):6-11.
	HUANG Bojie, CAO Yonghong, HUA Jianmin, et al. Maximum self supporting depth of pile hole considering the effect of circular arch[J]. Journal of Civil, Architectural & Environmental Engineering, 2018, 40(2):6-11.
[10]	李林, 李镜培, 岳著文, 等. 饱和黏土中钻孔灌注桩孔壁稳定性力学机制研究[J]. 岩土力学, 2016, 37(9):2496-2504.
	LI Lin, LI Jingpei, YUE Zhuwen, et al. Mechanical mechanism of hole-wall stability of bored pile in saturated clay[J]. Rock and Soil Mechanics, 2016, 37(9):2496-2504.
[11]	别列赞采夫 V G. 松散体(土壤)极限平衡的轴对称问题[M]. 谢宗樑,黄贻吉. 北京: 建筑工程出版社, 1956.
	BEREZANTZEV V G. Axisymmetric problem of limit equilibrium for loose bodies (soil) [M]. XIE Zongliang, HUANG Yiji. Beijing: Architectural Engineering Press, 1956.
[12]	XIONG G J, WANG J H. A rigorous characteristic line theory for axisymmetric problems and its application in circular excavations[J]. Acta Geotechnica, 2020, 15(2):439-453. doi: 10.1007/s11440-018-0697-7 URL
[13]	XIONG G J, WANG J H, CHEN J J. Theory and practical calculation method for axisymmetric active earth pressure based on the characteristics method considering the compatibility condition[J]. Applied Mathematical Modelling, 2019, 68:563-582. doi: 10.1016/j.apm.2018.11.022 URL
[14]	中华人民共和国住房和城乡建设部. 建筑桩基技术规范: JGJ94-2008[S]. 北京: 中国建筑工业出版社, 2008: 86-87.
	Ministry of Housing and Urban-Rural Development of the People’s Republic of China. Technical code for building pile foundation: JGJ94-2008[S]. Beijing: China Architecture and Building Press, 2008: 86-87.
[15]	LIU F Q, WANG J H, ZHANG L L. Axi-symmetric active earth pressure obtained by the slip line method with a general tangential stress coefficient[J]. Computers and Geotechnics, 2009, 36(1/2):352-358. doi: 10.1016/j.compgeo.2008.02.002 URL
[16]	CHENG Y M, HU Y Y, WEI W B. General axisymmetric active earth pressure by method of characteristics—Theory and numerical formulation[J]. International Journal of Geomechanics, 2007, 7(1):1-15. doi: 10.1061/(ASCE)1532-3641(2007)7:1(1) URL
[17]	YU M H, LI J C, ZHANG Y Q. Unified characteristics line theory of spacial axisymmetric plastic problem[J]. Science in China Series E: Technolgical Science, 2001, 44(2):207-215.
[18]	TOBAR T, MEGUID M A. Experimental study of the earth pressure distribution on cylindrical shafts[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2011, 137(11):1121-1125. doi: 10.1061/(ASCE)GT.1943-5606.0000535 URL
[19]	TRAN V D H, YACOUB T E, MEGUID M A. On the analysis of vertical shafts in soft ground: Evaluating soil-structure interaction using two different numerical modeling techniques[EB/OL]. [2018-06-01]. https://www.researchgate.net/publication/257578341.

φ/(°)	l_γ	m_γ	n_γ	l_q	m_q	n_q
0	0	1	0	0.9765	0.0002	0
5	0.1049	0.9307	-0.0004	0.9410	0.0023	-0.0000
10	0.2588	0.8366	-0.0011	0.8996	0.0043	-0.0001
15	0.4425	0.7208	-0.0019	0.8511	0.0060	-0.0001
20	0.6857	0.5499	-0.0029	0.7945	0.0073	-0.0001
25	0.8151	0.4470	-0.0031	0.7290	0.0080	-0.0001
30	0.9475	0.3050	-0.0030	0.6537	0.0079	-0.0001
35	0.9879	0.1761	-0.0024	0.5684	0.0068	-0.0001