强夯置换法处理淤泥质黏性土地基加固特性试验研究
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摘要
针对山东日照市某淤泥质黏性土钢铁精品基地工程,结合理论分析,通过置换墩载荷试验、螺旋板载荷试验、孔隙水压力试验、标准贯入试验、地质雷达探测等多种原位测试手段及室内土工试验,探讨了强夯置换加固淤泥质黏性土地基的作用机理、加固机制以及有效加固深度。试验结果表明,强夯置换墩的墩长为7.5～9.0m,置换墩的承载力分别为1250kN、1173kN,承载力满足要求;强夯对浅层墩间土有明显的加固效果;强夯过程中孔隙水压力呈波浪型分布,介于21～110kPa之间,静置2d左右,可以有效减小强夯过程中引起的孔隙水压力,且强夯一遍后静置5d左右孔隙水压力基本消散至夯前水平;经过强夯,消除了第五层粉细砂土的液化。研究成果可为同类地区强夯置换工程的设计、施工及检测提供参考。
The reinforcement mechanism and effective treatment depth of soft clay improved by dynamic compaction replacement method are discussed through loading test on replacement pier, spiral plate load test, pore pressure test, standard penetration test, ground penetration radar detection and indoor laboratory tests of a steel base project in Rizhao, Shandong Province, China. The results show that when the pier length of dynamic compaction replacement pier is 7.5～9.0 m, the bearing capacity of the pier is 1250 kN and 1173 kN respectively which meets the engineering requirement; the shallow soil between piers can be improved obviously; the distribution of pore water pressure range from 21 kPa to 110 kPa in undulating form during the tampping process and will reduce effectively in 2 days and disappear in 5 days; the liquefaction of fine sand will eliminate after compaction. The conclusions of the paper could be referred for the design, construction and testing for dynamic compaction replacement projects in the same area.
The reinforcement mechanism and effective treatment depth of soft clay improved by dynamic compaction replacement method are discussed through loading test on replacement pier, spiral plate load test, pore pressure test, standard penetration test, ground penetration radar detection and indoor laboratory tests of a steel base project in Rizhao, Shandong Province, China. The results show that when the pier length of dynamic compaction replacement pier is 7.5～9.0 m, the bearing capacity of the pier is 1250 kN and 1173 kN respectively which meets the engineering requirement; the shallow soil between piers can be improved obviously; the distribution of pore water pressure range from 21 kPa to 110 kPa in undulating form during the tampping process and will reduce effectively in 2 days and disappear in 5 days; the liquefaction of fine sand will eliminate after compaction. The conclusions of the paper could be referred for the design, construction and testing for dynamic compaction replacement projects in the same area.
引文
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[12] 闫楠, 白晓宇, 水伟厚等. 陆域与海域深厚碎石回填地基高能级强夯有效加固深度对比试验研究[J]. 中南大学学报 (自然科学版), 2017, 48(7): 1891～1900.Yan Nan, Bai Xiaoyu, Shui Weihou et al. Comparative experimental research of effective reinforced depth of high energy dynamic compaction on foundation backfilled by crushed stone in land area and sea area[J]. Journal of Central South University (Science and Technology), 2017, 48(7): 1891～1900. (in Chinese)
[13] 水伟厚. 对强夯置换概念的探讨和置换墩长度的实测研究[J]. 岩土力学, 2011, 32(3): 3～10.Shui Weihou. Exploring concept of dynamic replacement and measured length of replacement pier[J]. Rock and Soil Mechanics, 2011, 32(3): 3～10. (in Chinese)
[14] 白冰, 徐华轩, 刘海波等. 强夯置换法处理松软土地基若干问题研究[J]. 岩石力学与工程学报, 2010, 29(增刊1): 3001～3006.Bai Bing, Xu Huaxuan, Liu Haibo et al. Some problems on dynamic replacement method to improve soft soil ground[J]. Chinese Journal of Rock Mechanics and Engineering, 2010, 29(S1):3001～3006. (in Chinese)
[15] 中华人民共和国国家标准. 建筑地基基础设计规范(GB 50007-2011)[S]. 北京: 中国建筑工业出版社, 2011.The State Standards of the People′s Republic of China. Code for design of building foundation (GB 50007-2011)[S]. Beijing: China Architecture and Building Press, 2011. (in Chinese)
[16] 谢昭宇. 螺旋板载荷试验改进及成果应用[J]. 工程勘察, 2008, 36(6): 13～15.Xie Zhaoyu. Spiral plate load test improvement and application of results[J]. Geotechnical Investigation & Surveying, 2008, 36(6): 13～15. (in Chinese)
[17] 常士骠, 张苏民, 项勃. 工程地质手册(第四版)[M]. 北京: 中国建筑工业出版社, 2007.Chang Shibiao, Zhang Sumin, Xiang Bo. Engineering geology handbook (Fourth Edition)[M]. Beijing: China Architecture and Building Press, 2007. (in Chinese)
[18] 刘新荣, 刘永权, 杨忠平等. 基于地质雷达的隧道综合超前预报技术[J]. 岩土工程学报, 2015, 37(增刊2): 51～56. Liu Xinlong, Liu Yongquan, Yang Zhongping et al. Synthetic advanced geological prediction technology for tunnels based on GPR[J]. Chinese Journal of Geotechnical Engineering, 2015, 37(S2): 51～56. (in Chinese)
[19] 何国富, 涂强, 孙亮富. 地质雷达在含块石填土场地探测中的应用[J]. 勘察科学技术, 2016, (4): 55～57.He Guofu, Tu Qiang, Sun Liangfu. Application of ground penetration radar in detection of backfill field with block stone[J].Site Investigation Science and Technology, 2016, (4):55～57. (in Chinese)
[2] 曾庆军, 李茂英, 李大勇. 强夯置换深度的估算[J]. 岩土工程学报, 2002, 24(5): 608～611.Zeng Qingjun, Li Maoying, Li Dayong. Estimation of the displacement depth in dynamic replacement [J]. Chinese Journal of Geotechnical Engineering,2002, 24(5):608～611. (in Chinese)
[3] 赵亮. 干硬性混凝土强夯置换单墩复合地基的探讨[J]. 工程勘察, 2013, 41(10): 29～32.Zhao Liang. Discussion on composite ground of single dynamic replacement pier of dry concrete[J]. Geotechnical Investigation & Surveying, 2013, 41(10):29～32. (in Chinese)
[4] 张桂英.应用强夯置换法处理软弱路基[J]. 交通世界, 2007, (1): 68～69.Zhang Guiying. The application of soft soils subgrade treatment with the methods of dynamic compaction replacement[J]. Transpoworld, 2007,(1): 68～69. (in Chinese)
[5] 王宏祥, 冯守中, 闫澍旺. 强夯置换墩加固高寒湿地公路软基的研究[J]. 工程勘察, 2009, 37(4): 15～20.Wang Hongxiang, Feng Shouzhong, Yan Shuwang. Study on dynamic replacement for the consolidation of highway soft subgrade in high-cold wetlands[J].Geotechnical Investigation & Surveying,2009, 37(4): 15～20. (in Chinese)
[6] 徐东升, 汪稔, 孟庆山等. 海相淤泥软土地基强夯置换砂桩试验分析[J]. 岩土力学, 2009, 30(12): 3831～3836.Xu Dongsheng, Wang Ren, Meng Qingshan et al. Field test analysis of dynamic consolidation and replacement sand pile on marine soft soil[J]. Rock and Soil Mechanics, 2009, 30(12): 3831～3836. (in Chinese)
[7] 董伟, 闫澍旺, 冯守中等. 采用强夯置换墩加固湿地中高速公路路基的研究[J]. 岩石力学与工程学报, 2009, 28(增刊1): 2966～2972.Dong Wei, Yan Shuwang, Feng Shouzhong et al. Study on dynamic compaction replacement for reinforcing freeway roadbed in wetlands[J]. Chinese Journal of Rock Mechanics and Engineering, 2009, 28(S1): 2966～2972. (in Chinese)
[8] 张彧, 房建宏, 刘建坤等. 强夯置换复合地基加固盐渍土效果的试验研究[J]. 岩土工程学报, 2011, 33(增刊1): 251～254.Zhang Yu, Fang Jianhong, Liu Jiankun et al. Field tests on reinforcement effects of ground treatment of composite foundation in saline soils by dynamic compaction replacement[J].Chinese Journal of Geotechnical Engineering, 2011, 33(S1): 251～254. (in Chinese)
[9] 郑凌逶, 周风华. 强夯置换软土中碎石墩形成过程的试验研究[J]. 岩土力学, 2014, 35(1): 90～97.Zheng Lingwei, Zhou Fenghua. Experimental study of forming process of replacement pier in soft soil using dynamic replacement method[J].Rock and Soil Mechanics, 2014, 35(1): 90～97. (in Chinese)
[10] 谢新宇, 徐玉胜, 吴健等. 软土地基连续强夯置换碎石墩的数值分析[J]. 西北地震学报, 2011, 33(3): 249～254.Xie Xinyu, Xu Yusheng, Wu Jian et al. Numerical simulation of stone column replacement by consecutive dynamic compaction in soft ground[J]. Northwestern Seismological Journal, 2011, 33(3): 249～254. (in Chinese)
[11] 李惠玲, 徐玉胜, 胡荣华. 强夯置换处理软土地基的现场试验研究[J]. 工业建筑, 2012, 42(10): 83～88.Li Huiling, Xu Yusheng, Hu Ronghua. Field test research on dynamic replacement for treatment of soft subsoil[J]. Industrial Construction, 2012, 42(10):83～88. (in Chinese)
[12] 闫楠, 白晓宇, 水伟厚等. 陆域与海域深厚碎石回填地基高能级强夯有效加固深度对比试验研究[J]. 中南大学学报 (自然科学版), 2017, 48(7): 1891～1900.Yan Nan, Bai Xiaoyu, Shui Weihou et al. Comparative experimental research of effective reinforced depth of high energy dynamic compaction on foundation backfilled by crushed stone in land area and sea area[J]. Journal of Central South University (Science and Technology), 2017, 48(7): 1891～1900. (in Chinese)
[13] 水伟厚. 对强夯置换概念的探讨和置换墩长度的实测研究[J]. 岩土力学, 2011, 32(3): 3～10.Shui Weihou. Exploring concept of dynamic replacement and measured length of replacement pier[J]. Rock and Soil Mechanics, 2011, 32(3): 3～10. (in Chinese)
[14] 白冰, 徐华轩, 刘海波等. 强夯置换法处理松软土地基若干问题研究[J]. 岩石力学与工程学报, 2010, 29(增刊1): 3001～3006.Bai Bing, Xu Huaxuan, Liu Haibo et al. Some problems on dynamic replacement method to improve soft soil ground[J]. Chinese Journal of Rock Mechanics and Engineering, 2010, 29(S1):3001～3006. (in Chinese)
[15] 中华人民共和国国家标准. 建筑地基基础设计规范(GB 50007-2011)[S]. 北京: 中国建筑工业出版社, 2011.The State Standards of the People′s Republic of China. Code for design of building foundation (GB 50007-2011)[S]. Beijing: China Architecture and Building Press, 2011. (in Chinese)
[16] 谢昭宇. 螺旋板载荷试验改进及成果应用[J]. 工程勘察, 2008, 36(6): 13～15.Xie Zhaoyu. Spiral plate load test improvement and application of results[J]. Geotechnical Investigation & Surveying, 2008, 36(6): 13～15. (in Chinese)
[17] 常士骠, 张苏民, 项勃. 工程地质手册(第四版)[M]. 北京: 中国建筑工业出版社, 2007.Chang Shibiao, Zhang Sumin, Xiang Bo. Engineering geology handbook (Fourth Edition)[M]. Beijing: China Architecture and Building Press, 2007. (in Chinese)
[18] 刘新荣, 刘永权, 杨忠平等. 基于地质雷达的隧道综合超前预报技术[J]. 岩土工程学报, 2015, 37(增刊2): 51～56. Liu Xinlong, Liu Yongquan, Yang Zhongping et al. Synthetic advanced geological prediction technology for tunnels based on GPR[J]. Chinese Journal of Geotechnical Engineering, 2015, 37(S2): 51～56. (in Chinese)
[19] 何国富, 涂强, 孙亮富. 地质雷达在含块石填土场地探测中的应用[J]. 勘察科学技术, 2016, (4): 55～57.He Guofu, Tu Qiang, Sun Liangfu. Application of ground penetration radar in detection of backfill field with block stone[J].Site Investigation Science and Technology, 2016, (4):55～57. (in Chinese)