A discussion of the test pressure of collapsible coefficient for Q<sub>2</sub> loess

LI Tonglu; FENG Wenqing; LIU Zhiwei; GAO Jianwei; FU Yukai; LEI Yulu; LI Ping

doi:10.16030/j.cnki.issn.1000-3665.202211006

2023 Vol. 50, No. 6

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LI Tonglu, FENG Wenqing, LIU Zhiwei, GAO Jianwei, FU Yukai, LEI Yulu, LI Ping. A discussion of the test pressure of collapsible coefficient for Q2 loess[J]. Hydrogeology & Engineering Geology, 2023, 50(6): 59-68. doi: 10.16030/j.cnki.issn.1000-3665.202211006

Citation:

LI Tonglu, FENG Wenqing, LIU Zhiwei, GAO Jianwei, FU Yukai, LEI Yulu, LI Ping. A discussion of the test pressure of collapsible coefficient for Q₂ loess[J]. Hydrogeology & Engineering Geology, 2023, 50(6): 59-68. doi: 10.16030/j.cnki.issn.1000-3665.202211006

A discussion of the test pressure of collapsible coefficient for Q₂ loess

1.
School of Geological Engineering and Geomatics, Chang’an University, Xi’an, Shaanxi　710054, China
2.
Observation and Research Station of Water Cycle and Geological Environment for the Chinese Loess Plateau, Ministry of Education, Zhengning, Gansu　745399, China
3.
Northwest Electric Power Design Institute Co. Ltd., of China Power Engineering Consulting Group, Xi’an, Shaanxi　710054, China

Received Date: 01 November 2022

Revised Date: 23 February 2023

Publish Date: 15 November 2023

Abstract

Abstract

Collapsible coefficient is an index to evaluate loess collapsibility, which is measured by laboratory test with collected intact samples. Collapsible coefficient varies with normal pressure loaded in test. It is better to use the real normal pressure in foundation when measuring the collapsible coefficient, but for reasons of convenience, the pressures are always designated as definite values in the codes or standards of construction in collapsible loess areas. However, the designated pressure for Q₃ (Malan) loess in the standards is reasonable and applicable, while that for Q₂ loess is still necessary to discuss. In this paper, the collapsible loess foundation of the Huaneng Electric Plant in Zhengning, Gansu Province is used as a case, the Q₂-Q₄ loess samples were collected in a 35.0 m deep shaft in 1 m intervals and the basic physical properties were measured in laboratory first. The collapsible coefficient is measured with the double oedometer method under low to high pressure for all the samples. Based on the test results, the collapsible coefficient with respect to depth determined with the present used GB 50025—2018 standard and the real pressure in foundation in the cases of various basement widths and basement pressures are compared. The results show that (1) the coefficient of collapsibility has a peak value. The initial collapse pressure and peak collapse pressure of Q₃ loess are higher than those of Q₂ loess. The peak coefficient of collapsibility of Q₃ loess is higher than that of Q₂ loess, which decreases with depth. (2) For Q₃ loess, the collapsible coefficient and subsidence determined by the pressure of the present standard are close to those determined by the real pressure in foundation, while for Q₂ loess, those determined by the pressure of the present standard in foundation deviates increasingly with depth to those determined by the real pressure. (3) Therefore, a modified test pressure for measuring collapsible coefficient of loess is proposed. It is demonstrated that the collapsible coefficients determined by the modified test pressure agree well with those by the real soil pressure.
- loess /
- test pressure /
- coefficient of collapsibility /
- double oedometer method /
- actual pressure

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References

[1]	中华人民共和国住房和城乡建设部. 湿陷性黄土地区建筑标准:GB 50025—2018[S]. 北京:中国建筑工业出版社,2019. [Ministry of Housing and Urban-Rural Development of the People’s Republic of China. Code for building construction in collapsible loess regions:GB 50025—2018[S]. Beijing:China Architecture & Building Press,2019. (in Chinese) Google Scholar Ministry of Housing and Urban-Rural Development of the People’s Republic of China. Code for building construction in collapsible loess regions: GB 50025—2018[S]. Beijing: China Architecture & Building Press, 2019. （in Chinese） Google Scholar
[2]	朱晓明,吴杨杰. 自主性的历史坐标——中国三线建设时期《湿陷性黄土地区建筑规范》(BJG 20—66)的编制研究[J]. 时代建筑,2019(6):58 − 63. [ZHU Xiaoming,WU Yangjie. Historical coordinates of self-reliance: A compilation study of building code for collapsible loess area (BJG 20—66) in the early days of the third front construction in China[J]. Times Architecture,2019(6):58 − 63. (in Chinese with English abstract) Google Scholar ZHU Xiaoming, WU Yangjie. Historical coordinates of self-reliance: A compilation study of building code for collapsible loess area （BJG 20—66） in the early days of the third front construction in China[J]. Times Architecture, 2019（6）: 58 − 63. （in Chinese with English abstract） Google Scholar
[3]	《湿陷性黄土地区建筑规范》管理组. 《湿陷性黄土地区建筑规范》TJ 25—78简介[J]. 工程勘察. 1980,(2):31 − 35. [Management Team of Code for building construction in collapsible loess regions. Brief introduction of building code for collapsible loess area TJ 25—78[J]. Geotechnical Investigation & Surveying,1980,8(2):31 − 35. (in Chinese) Google Scholar Management Team of Code for building construction in collapsible loess regions. Brief introduction of building code for collapsible loess area TJ 25—78[J]. Geotechnical Investigation & Surveying, 1980, 8（2）: 31 − 35. （in Chinese） Google Scholar
[4]	中华人民共和国行业标准编写组. 湿陷性黄土地区建筑规范:GBJ 25—1990[S]. 北京:中国计划出版社,1991. [The Professional Standards Compilation Group of People’s Republic of China. Code for building construction in collapsible loess regions (GBJ 25—1990)[S]. Beijing:China Planning Press,1991. (in Chinese) Google Scholar The Professional Standards Compilation Group of People’s Republic of China. Code for building construction in collapsible loess regions （GBJ 25—1990）[S]. Beijing: China Planning Press, 1991. （in Chinese） Google Scholar
[5]	中华人民共和国建设部. 湿陷性黄土地区建筑规范:GB 50025—2004[S]. 北京:中国建筑工业出版社,2004. [Ministry of Construction of the People’s Republic of China. Code for building construction in collapsible loess regions:GB 50025—2004[S]. Beijing:China Architecture & Building Press,2004. (in Chinese) Google Scholar Ministry of Construction of the People’s Republic of China. Code for building construction in collapsible loess regions: GB 50025—2004[S]. Beijing: China Architecture & Building Press, 2004. （in Chinese） Google Scholar
[6]	阚敦莉. 月坛金融中心结构与地基基础设计[J]. 建筑结构,2020,50(20):38 − 43. [KAN Dunli. Design on structure and foundation of Yuetan Financial Center[J]. Building Structure,2020,50(20):38 − 43. (in Chinese with English abstract) doi: 10.19701/j.jzjg.2020.20.006 CrossRef Google Scholar KAN Dunli. Design on structure and foundation of Yuetan Financial Center[J]. Building Structure, 2020, 50（20）: 38 − 43. （in Chinese with English abstract） doi: 10.19701/j.jzjg.2020.20.006 CrossRef Google Scholar
[7]	雷晓雨,闫明礼,申雪静,等. 地下水对地基基础设计的影响[J]. 工业建筑,2010,40(11):85 − 87. [LEI Xiaoyu,YAN Mingli,SHEN Xuejing,et al. Effect of groundwater design of building foundation[J]. Industrial Construction,2010,40(11):85 − 87. (in Chinese with English abstract) doi: 10.13204/j.gyjz2010.11.019 CrossRef Google Scholar LEI Xiaoyu, YAN Mingli, SHEN Xuejing, et al. Effect of groundwater design of building foundation[J]. Industrial Construction, 2010, 40（11）: 85 − 87. （in Chinese with English abstract） doi: 10.13204/j.gyjz2010.11.019 CrossRef Google Scholar
[8]	白琳,曹松涛. 盘南电厂煤系地层地基基础设计[J]. 武汉大学学报(工学版),2009,42(增刊1):281 − 283. [BAI Lin,CAO Songtao. Design of building foundations of Pannan Power Plant in coal stratum[J]. Engineering Journal of Wuhan University,2009,42(Sup 1):281 − 283. (in Chinese with English abstract) Google Scholar BAI Lin, CAO Songtao. Design of building foundations of Pannan Power Plant in coal stratum[J]. Engineering Journal of Wuhan University, 2009, 42（Sup 1）: 281 − 283. （in Chinese with English abstract） Google Scholar
[9]	宋岳. 引黄入晋工程大梁水库坝基黄土湿陷变形特征及对工程的影响[J]. 工程地质学报,1995,3(3):43 − 49. [SONG Yue. Characteristics of subsidence deformation of loess andtheir effect on the dam foundation of daliang reserivor[J]. Journal of Engineering Geology,1995,3(3):43 − 49. (in Chinese with English abstract) Google Scholar SONG Yue. Characteristics of subsidence deformation of loess andtheir effect on the dam foundation of daliang reserivor[J]. Journal of Engineering Geology, 1995, 3（3）: 43 − 49. （in Chinese with English abstract） Google Scholar
[10]	刘江龙,刘文剑,吴湘滨,等. 基于GIS广州市主城区地面塌陷危险性评价[J]. 工程地质学报,2007,15(5):630 − 634. [LIU Jianglong,LIU Wenjian,WU Xiangbin,et al. Gis-based hazard appraisement of ground collapse in downtown area of Guangzhou City[J]. Journal of Engineering Geology,2007,15(5):630 − 634. (in Chinese with English abstract) doi: 10.3969/j.issn.1004-9665.2007.05.008 CrossRef Google Scholar LIU Jianglong, LIU Wenjian, WU Xiangbin, et al. Gis-based hazard appraisement of ground collapse in downtown area of Guangzhou City[J]. Journal of Engineering Geology, 2007, 15（5）: 630 − 634. （in Chinese with English abstract） doi: 10.3969/j.issn.1004-9665.2007.05.008 CrossRef Google Scholar
[11]	张严,朱武,赵超英,等. 佛山地铁塌陷InSAR时序监测及机理分析[J]. 工程地质学报,2021,29(4):1167 − 1177. [ZHANG Yan,ZHU Wu,ZHAO Chaoying,et al. Moniting and inversion of Foshan metro collapse with multi-temporal insar and field investigation[J]. Journal of Engineering Geology,2021,29(4):1167 − 1177. (in Chinese with English abstract) doi: 10.13544/j.cnki.jeg.2019-557 CrossRef Google Scholar ZHANG Yan, ZHU Wu, ZHAO Chaoying, et al. Moniting and inversion of Foshan metro collapse with multi-temporal insar and field investigation[J]. Journal of Engineering Geology, 2021, 29（4）: 1167 − 1177. （in Chinese with English abstract） doi: 10.13544/j.cnki.jeg.2019-557 CrossRef Google Scholar
[12]	王云龙,陈晔,郭海朋等. 沧州地区土层固结特征与地面沉降临界水位研究[J]. 水文地质工程地质,2023,50(4):185 – 192. [WANG Yunlong,CHEN Hua,GUO Haipeng,et al. A study of the critical groundwater level related to soil consolidation characteristics of land subsidence in Cangzhou[J]. Hydrogeology & Engineering Geology,2023,50(4):185 – 192. (in Chinese with English abstract) Google Scholar
[13]	方祥位,申春妮,李春海,等. 陕西蒲城Q₂黄土湿陷变形特性研究[J]. 岩土力学,2013,34(增刊2):115 − 120. [FANG Xiangwei,SHEN Chunni,LI Chunhai,et al. Collapsible deformation properties of Q₂ loess in Pucheng of Shaanxi Province[J]. Rock and Soil Mechanics,2013,34(Sup 2):115 − 120. (in Chinese with English abstract) Google Scholar FANG Xiangwei, SHEN Chunni, LI Chunhai, et al. Collapsible deformation properties of Q₂ loess in Pucheng of Shaanxi Province[J]. Rock and Soil Mechanics, 2013, 34（Sup 2）: 115 − 120. （in Chinese with English abstract） Google Scholar
[14]	方祥位,申春妮,汪龙,等. Q₂黄土浸水前后微观结构变化研究[J]. 岩土力学,2013,34(5):1319 − 1324. [FANG Xiangwei,SHEN Chunni,WANG Long,et al. Research on microstructure of Q₂ loess before and after wetting[J]. Rock and Soil Mechanics,2013,34(5):1319 − 1324. (in Chinese with English abstract) Google Scholar FANG Xiangwei, SHEN Chunni, WANG Long, et al. Research on microstructure of Q₂ loess before and after wetting[J]. Rock and Soil Mechanics, 2013, 34（5）: 1319 − 1324. （in Chinese with English abstract） Google Scholar
[15]	张炜,张苏民. 我国黄土工程性质研究的发展[J]. 岩土工程学报,1995,17(6):80 − 88. [ZHANG Wei,ZHANG Sumin. Development of loess engineering properties research in China[J]. Chinese Journal of Geotechnical Engineering,1995,17(6):80 − 88. (in Chinese with English abstract) doi: 10.3321/j.issn:1000-4548.1995.06.011 CrossRef Google Scholar ZHANG Wei, ZHANG Sumin. Development of loess engineering properties research in China[J]. Chinese Journal of Geotechnical Engineering, 1995, 17（6）: 80 − 88. （in Chinese with English abstract） doi: 10.3321/j.issn:1000-4548.1995.06.011 CrossRef Google Scholar
[16]	谢定义. 试论我国黄土力学研究中的若干新趋向[J]. 岩土工程学报,2001,23(1):3 − 13. [XIE Dingyi. Exploration of some new tendencies in research of loess soil mechanics[J]. Chinese Journal of Geotechnical Engineering,2001,23(1):3 − 13. (in Chinese with English abstract) doi: 10.3321/j.issn:1000-4548.2001.01.002 CrossRef Google Scholar XIE Dingyi. Exploration of some new tendencies in research of loess soil mechanics[J]. Chinese Journal of Geotechnical Engineering, 2001, 23（1）: 3 − 13. （in Chinese with English abstract） doi: 10.3321/j.issn:1000-4548.2001.01.002 CrossRef Google Scholar
[17]	汤连生. 黄土湿陷性的微结构不平衡吸力成因论[J]. 工程地质学报,2003,11(1):30 − 35. [TANG Liansheng. Synthetic effect of microstructure and uneven suction on loess subsidence[J]. Journal of Engineering Geology,2003,11(1):30 − 35. (in Chinese with English abstract) doi: 10.3969/j.issn.1004-9665.2003.01.006 CrossRef Google Scholar TANG Liansheng. Synthetic effect of microstructure and uneven suction on loess subsidence[J]. Journal of Engineering Geology, 2003, 11（1）: 30 − 35. （in Chinese with English abstract） doi: 10.3969/j.issn.1004-9665.2003.01.006 CrossRef Google Scholar
[18]	邵生俊,李骏,李国良,等. 大厚度自重湿陷黄土湿陷变形评价方法的研究[J]. 岩土工程学报,2015,37(6):965 − 978. [SHAO Shengjun,LI Jun,LI Guoliang,et al. Evaluation method for self-weight collapsible deformation of large thickness loess foundation[J]. Chinese Journal of Geotechnical Engineering,2015,37(6):965 − 978. (in Chinese with English abstract) doi: 10.11779/CJGE201506001 CrossRef Google Scholar SHAO Shengjun, LI Jun, LI Guoliang, et al. Evaluation method for self-weight collapsible deformation of large thickness loess foundation[J]. Chinese Journal of Geotechnical Engineering, 2015, 37（6）: 965 − 978. （in Chinese with English abstract） doi: 10.11779/CJGE201506001 CrossRef Google Scholar
[19]	史向庆. 湿陷性黄土湿陷系数测定方法探讨[J]. 土工基础,2018,32(3):355 − 356. [SHI Xiangqing. Methods of determining the coefficient of wetting collapsibility of collapsible loess[J]. Soil Engineering and Foundation,2018,32(3):355 − 356. (in Chinese with English abstract) Google Scholar SHI Xiangqing. Methods of determining the coefficient of wetting collapsibility of collapsible loess[J]. Soil Engineering and Foundation, 2018, 32（3）: 355 − 356. （in Chinese with English abstract） Google Scholar
[20]	胡燕妮,米海珍. 兰州高坪黄土湿陷系数的试验压力取值探讨[J]. 兰州理工大学学报,2008,34(6):135 − 138. [HU Yanni,MI Haizhen. Investigation in magnitude evaluation of collapsibility coefficient of loess on high fluvial terrace in Lanzhou by means of pressure testing[J]. Journal of Lanzhou University of Technology,2008,34(6):135 − 138. (in Chinese with English abstract) doi: 10.3969/j.issn.1673-5196.2008.06.032 CrossRef Google Scholar HU Yanni, MI Haizhen. Investigation in magnitude evaluation of collapsibility coefficient of loess on high fluvial terrace in Lanzhou by means of pressure testing[J]. Journal of Lanzhou University of Technology, 2008, 34（6）: 135 − 138. （in Chinese with English abstract） doi: 10.3969/j.issn.1673-5196.2008.06.032 CrossRef Google Scholar
[21]	常帅斌,陈明,张虎元,等. 陇东地区早胜塬古土壤膨胀特性研究[J]. 铁道建筑技术,2020(9):7 − 11. [CHANG Shuaibin,CHEN Ming,ZHANG Huyuan,et al. Swelling characteristics of loess paleosol in Zaosheng tableland of longdong area[J]. Railway Construction Technology,2020(9):7 − 11. (in Chinese with English abstract) doi: 10.3969/j.issn.1009-4539.2020.09.002 CrossRef Google Scholar CHANG Shuaibin, CHEN Ming, ZHANG Huyuan, et al. Swelling characteristics of loess paleosol in Zaosheng tableland of longdong area[J]. Railway Construction Technology, 2020（9）: 7 − 11. （in Chinese with English abstract） doi: 10.3969/j.issn.1009-4539.2020.09.002 CrossRef Google Scholar
[22]	常帅斌. 含水率对古土壤隧道围岩膨胀性的影响[J]. 铁道建筑,2020,60(6):60 − 64. [CHANG Shuaibin. Influence of water content on swelling of surrounding rock of paleosol tunnel[J]. Railway Engineering,2020,60(6):60 − 64. (in Chinese with English abstract) doi: 10.3969/j.issn.1003-1995.2020.06.14 CrossRef Google Scholar CHANG Shuaibin. Influence of water content on swelling of surrounding rock of paleosol tunnel[J]. Railway Engineering, 2020, 60（6）: 60 − 64. （in Chinese with English abstract） doi: 10.3969/j.issn.1003-1995.2020.06.14 CrossRef Google Scholar
[23]	魏伟. 隧道穿越膨胀性古土壤层衬砌结构受力特征及厚度优化[D]. 西安:西安科技大学,2020. [WEI Wei. Supporting characteristics and thickness optimization of tunnels through expansive paleosol layer[D]. Xi’an:Xi’an University of Science and Technology,2020. (in Chinese with English abstract) Google Scholar WEI Wei. Supporting characteristics and thickness optimization of tunnels through expansive paleosol layer[D]. Xi’an: Xi’an University of Science and Technology, 2020. （in Chinese with English abstract） Google Scholar
[24]	屈宏录,刘德仁,孙英萍,等. 深厚黄土地基浸水湿陷变形及竖向土压力作用分析[J]. 水文地质工程地质,2022,49(4):157 − 164. [QU Honglu,LIU Deren,SUN Yingping,et al. Analysis of collapsible deformation and vertical soil pressure action of thick loess foundation[J]. Hydrogeology & Engineering Geology,2022,49(4):157 − 164. (in Chinese with English abstract) Google Scholar QU Honglu, LIU Deren, SUN Yingping, et al. Analysis of collapsible deformation and vertical soil pressure action of thick loess foundation[J]. Hydrogeology & Engineering Geology, 2022, 49（4）: 157 − 164. （in Chinese with English abstract） Google Scholar
[25]	王新刚,刘凯,王友林,等. 典型黄土滑坡滑带土不同含水率下蠕变特性试验研究[J]. 水文地质工程地质,2022,49(5):137 − 143. [WANG Xingang,LIU Kai,WANG Youlin,et al. An experimental study of the creep characteristics of loess landslide sliding zone soil with different water content[J]. Hydrogeology & Engineering Geology,2022,49(5):137 − 143. (in Chinese with English abstract) Google Scholar WANG Xingang, LIU Kai, WANG Youlin, et al. An experimental study of the creep characteristics of loess landslide sliding zone soil with different water content[J]. Hydrogeology & Engineering Geology, 2022, 49（5）: 137 − 143. （in Chinese with English abstract） Google Scholar
[26]	王寒. 延安丘陵沟壑区高压力下Q₂、Q₃黄土湿陷特性及评价方法研究[D]. 兰州:兰州理工大学,2022. [WANG Han. Research on collapsibility and evaluation method of loess under high pressure in the hilly and gully region of Yan’an[D]. Lanzhou:Lanzhou University of Technology,2022. (in Chinese with English abstract) Google Scholar WANG Han. Research on collapsibility and evaluation method of loess under high pressure in the hilly and gully region of Yan’an[D]. Lanzhou: Lanzhou University of Technology, 2022. （in Chinese with English abstract） Google Scholar