STUDY ON RAPID EVALUATION OF SELF-WEIGHT COLLAPSIBILITY OF DEEP LOESS BASED ON STATIC PROBE TEST
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摘要: 湿陷性是制约黄土场地工程建设的最主要因素。针对黄土场地现场浸水试验测试时间长、成本高等问题,在兰州新区黄土场地和靖远黄河高阶地黄土场地进行静力触探试验,研究静力触探锥尖阻力、锥侧阻力沿土层深度的变化关系,并在现场取原状黄土试样进行室内湿陷试验,研究发现室内试验所测得的自重湿陷系数沿深度具有良好的线性关系,由此建立了静力触探所测锥尖、锥侧阻力与自重湿陷系数之间的联系,提出了一种通过静力触探试验结果快速评价黄土场地自重湿陷性的方法。基于上述方法,对兰州新区和靖远黄河阶地黄土场地其他点位的测试结果进行自重湿陷性评价,验证了该方法的可行性与准确性。Abstract: Collapsibility is the most important factor restricting loess site construction. Loess field test is long in time and high in cost. This paper carries out the static cone peneration test in the New District in Lanzhou loess ground and the Jingyuan Yellow River high terrace loess area. It examines the taper cone tip resistance relation between frictional resistance along the depth of soil layer. It takes the original state collapsibility loess samples for indoor test. It is found that the coefficient of self-weight collapsibility measured in laboratory tests has a good linear relationship along the depth,and the relationship between the cone tip resistance and the cone side resistance. The coefficient of self-weight collapsibility measured by static penetration test is established. A method for rapidly evaluating self-weight collapsibility of loess site is put forward based on the results of static penetration test. Based on the above studies,the self-weight collapsibility of loess sites in the Jingyuan Yellow River terrace and Lanzhou New Area is evaluated,and the feasibility and accuracy of the method are verified.
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表 1 黄土湿陷系数与湿陷等级的对应关系
Table 1. Corresponding relationship between loess collapsibility coefficient and collapsibility grade
湿陷系数范围 湿陷等级 δS>0.07 强烈湿陷 0.03<δS<0.07 中等湿陷 0.015<δS<0.03 轻微湿陷 δS<0.015 无湿陷性 表 2 拟合系数取值表
Table 2. Table of values of fitting coefficients
黄土分布 A1 B1 A2 B2 兰州新区 -0.0201 0.1895 5.6×10-4 0.1740 靖远黄河阶地 0.0044 0.0390 9.1×10-5 0.0437 表 3 不同湿陷等级与静力触探数据的对应关系
Table 3. The corresponding relationship between different collapsibility grades and static penetration data
湿陷等级 兰州新区黄土 靖远黄河阶地黄土 qc fs qc fs 强烈 <5.69 <185.71 >7.05 >289.01 中等 5.69~7.94 185.71~257.14 <7.05 <289.01 轻微 7.94~8.68 257.14~283.93 — — 无 >8.68 >283.93 — — -
Cheng W, Zhao T Y. 2018. Study on physical and mechanical properties and evaluation of collapsibility loess of different landforms[J]. Safety and Environmental Engineering, 25 (6): 191-198. Fu Y. 2016. Correlation of the collapsibility of loess and the physical index[D]. Beijing: China University of Geosciences(Beijing). Gao Y, Ma Y X, Zhang W Y, et al. 2019. Analysis of humidifying deformation characteristics and microstructure of loess in Xining Area[J]. Journal of Engineering Geology, 27 (4): 803-810. He L X, Wang X, Zhang Y J, et al. 2018. Model test study on steam diffusion law of unsaturated loess[J]. Journal of Engineering Geology, 26 (5): 1265-1271. Huang Y, Wang Y S, Wu G H. 2018. Evaluate loess collapsibility based on fuzzy information optimization method[J]. Journal of Gansu Sciences, 34 (4): 94-99. Kang X J, Li B. 2008. Development status and future trend of static penetration technology abroad[J]. Geotechnical Engineering World, 11 (5): 63-65. doi: 10.3969/j.issn.1674-7801.2008.05.019 Liu Y, Wang J D. 2000. The method of fuzzy information processing of optimization in the evaluation of loess collapsibility[J]. Journal of Northwest University(Natural Science Edition), 30 (1): 78-82. Liu Y B, Chen H E, Xu X H, et al. 2020. Laboratory study on collapsibility of typical loess under unsaturated humidified conditions[J]. Journal of Engineering Geology, 28 (5): 973-981. Ma H P, Chen Z Y, Yu S. 2014. Correlations of soil shear strength with specific penetration resistance of CPT in Shanghai area[J]. Rock and Soil Mechanics, 35 (2): 536-542. The National Standard Compilation Group of the People's Republic of China. 2019. Code for building construction in collapsible loess regions(GB50025-2018)[S]. Beijing: China Architecture and Architecture Press. Wu X P, Zhao Y H, Xu A H, et al. 2018. Relationship between collapsibility and physical-mechanical indexes of loess and evaluation methods[J]. Journal of Yangtze River Scientific Research Institute, 35 (6): 75-80. Xie W L, Wang J D, Zhang X J, et al. 2005. Application in evaluation of loess collapsibility with the method of fuzzy information optimization processing[J]. Journal of Northwest University(Natural Science Edition), 35 (1): 95-99. Zhou S H, Wei L Y, Wu F Q, et al. 1999. Study on geotechnical properties of loess with the help of a portable dynamic penetrometer[J]. Chinese Journal of Geotechnical Engineering, 21 (6): 719-722. doi: 10.3321/j.issn:1000-4548.1999.06.019 陈伟, 赵天宇. 2018. 不同地貌黄土的物理力学特性和湿陷性评价[J]. 安全与环境工程, 25 (6): 191-198. https://www.cnki.com.cn/Article/CJFDTOTAL-KTAQ201806030.htm 付宇. 2016. 黄土湿陷性与物理指标相关性研究[D]. 北京: 中国地质大学(北京). 高英, 马艳霞, 张吾渝, 等. 2019. 西宁地区黄土增湿变形特性及微观结构分析[J]. 工程地质学报, 27 (4): 803-810. doi: 10.13544/j.cnki.jeg.yt2019416 黄宇, 王延寿, 吴光辉. 2018. 基于模糊信息优化方法的黄土湿陷性评价[J]. 甘肃科学学报, 30 (4): 94-99. https://www.cnki.com.cn/Article/CJFDTOTAL-GSKX201804017.htm 康晓娟, 李波. 2008. 国外静力触探技术发展现状及未来趋势[J]. 岩土工程界, 11 (5): 63-65. https://www.cnki.com.cn/Article/CJFDTOTAL-YSJS200805016.htm 刘弋博, 陈慧娥, 许晓慧, 等. 2020. 非饱和增湿条件下典型黄土湿陷性研究[J]. 工程地质学报, 28 (5): 973-981. doi: 10.13544/j.cnki.jeg.2020-357 何陇霞, 王旭, 张延杰, 等. 2018. 非饱和黄土水蒸气扩散规律模型试验研究[J]. 工程地质学报, 26 (5): 1265-1271. doi: 10.13544/j.cnki.jeg.2018111 刘悦, 王家鼎. 2000. 黄土湿陷性评价中的模糊信息优化处理方法[J]. 西北大学学报(自然科学版), 30 (1): 78-82. https://www.cnki.com.cn/Article/CJFDTOTAL-XBDZ20050100O.htm 马海鹏, 陈祖煜, 于沭. 2014. 上海地区土体抗剪强度与静力触探比贯入阻力相关关系研究[J]. 岩土力学, 35 (2): 536-542. https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201402034.htm 武小鹏, 赵永虎, 徐安花, 等. 2018. 黄土湿陷性与其物理力学指标的关系及评价方法[J]. 长江科学院院报, 35 (6): 75-80. https://www.cnki.com.cn/Article/CJFDTOTAL-CJKB201806017.htm 谢婉丽, 王家鼎, 张新军, 等. 2005. 模糊信息优化方法在黄土湿陷性评价中的应用[J]. 西北大学学报(自然科学版), 35 (1): 95-99. https://www.cnki.com.cn/Article/CJFDTOTAL-XBDZ20050100O.htm 中华人民共和国国家标准编写组. 2019. 湿陷性黄土地区建筑规范(GB50025—2018)[S]. 北京: 中国建筑工业出版社. 周树华, 魏兰英, 伍法权, 等. 1999. 运用轻便动力触探仪研究黄土的岩土工程特性[J]. 岩土工程学报, 21 (6): 719-722. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC199906015.htm -