Effect analysis of percussive compaction and dynamic compaction on roadbed reinforcement
-
摘要: 在黄土地区陕西某高速公路段对原地基分别进行强夯与冲击碾压处理, 通过室内试验和现场原位测试, 对比了地基处理前后不同深度土体的物理力学指标(干密度、压缩模量与湿陷系数) 和微结构特征, 以及载荷板试验、触探试验、旁压试验结果, 研究了采用强夯和冲击碾压处理后黄土地基强度的形成机理、地基承载力变化、处理效果与有效影响深度。结果表明冲击碾压的有效影响深度在1.0~2.0 m, 在0~1.5 m处形成连续、均匀、密实的加固层; 强夯的有效加固深度达4.0 m, 有效影响深度在5.0~6.0 m, 在加固深度内湿陷性均被有效消除。Abstract: The highway bases of one section in the loess area of Shaanxi province were consolidated by percussive compaction and dynamic consolidation, the physical force indexes (dry density, constrained modulus and collapsibility coefficient) in different depths and the microstructure features of the loess were analyzed by soil engineering test in laboratory and original test, the results of plate loading test, cone penetration test and compressuremeter test were compared, the intensity forming mechanism of the loess roadbed and the changes, effects and valid influence depths of foundation bearing capacity in the loess area were analysed.Analysis result shows that the valid influence depth of dynamic consolidation ranges from 1.0 to 2.0 m, and successive, even, solid reinforcement layer is formed in the range between 0 and 1.5 m; for percussive compaction, the valid reinforcing depth reaches 4.0 m, the valid influence depths varies from 5.0 to 6.0 m, and the collapsibility is eliminated effectively in reinforcing depth. (2 tabs, )
-
图 7 单桥试验比贯入阻力沿深度的变化
Figure 7. Change of penetration resistance of single cone test with depth
图 8 双桥试验锥尖阻力沿深度的变化
Figure 8. Change of conic node resistancy cofficient of double cones test with depth
图 10 动力触探试验击数沿深度的变化
Figure 10. Change of blow counts of dynamic sounding test with depth
图 11 旁压试验承载力沿深度的变化
Figure 11. Change of bearing capacity of compressu- remeter test with depth
表 1 湿陷性指标
Table 1. Collapsibility indices
桩号 湿陷等级 湿陷系数 自重湿陷系数 总湿陷量 自重湿陷量 压缩系数 压缩性 K171+413~K172+500 Ⅲ级自重湿陷 0.041 0.030 48.1 35.8 0.49 中等 K174+170~K176+890 Ⅱ级自重湿陷 0.027 0.009 32.8 5.6 0.31 中等 
下载: 导出CSV
表 2 处理结果对比
Table 2. Comparison of treatment results
地基处理方法 分析指标 室内土工试验 触探试验 旁压试验 强夯压实 有效加固深度/m 4.0 4.0 4.0 有效影响深度/m 5.0~6.0 4.0~5.0 5.0~6.0 冲击压实 有效加固深度/m 0.5~1.0 0.5~1.0 0.5~1.0 有效影响深度/m 1.0~2.0 1.0~2.0 1.0~2.0
下载: 导出CSV
-
[1] 张洪亮, 胡长顺, 刘保健, 等. 压实石灰黄土力学特性试验[J]. 交通运输工程学报, 2003, 3(4): 13-16. doi: 10.3321/j.issn:1671-1637.2003.04.004Zhang Hong-liang, Hu Chang-shun, Liu Bao-jian, et al. Mechanical properties experiment of compacted loess-lime[J]. Journal of Traffic and Transportation Engineering, 2003, 3(4): 13-16. (in Chinese) doi: 10.3321/j.issn:1671-1637.2003.04.004 [2] 冯忠居, 冯瑞玲, 赵占厂, 等. 黄土湿陷性对桥梁桩基承载力的影响[J]. 交通运输工程学报, 2005, 5(3): 60-63. http://transport.chd.edu.cn/article/id/200503013Feng Zhong-ju, Feng Rui-ling, Zhao Zhan-chang, et al. Effect of collapsible loess on pile foundation bearing capacity[J]. Journal of Traffic and Transportation Engineering, 2005, 5(3): 60-63. (in Chinese) http://transport.chd.edu.cn/article/id/200503013 [3] 石刚, 王晋国, 支喜兰, 等. 黄土地区公路工程地基承载力分区计算方法[J]. 交通运输工程学报, 2005, 5(4): 48-52. http://transport.chd.edu.cn/article/id/200504010Shi Gang, Wang Jin-guo, Zhi Xi-lan, et al. Calculation method of foundation bearing capacity based on division in loess area for highway engineering[J]. Journal of Traffic and Transportation Engineering, 2005, 5(4): 48-52. (in Chinese) http://transport.chd.edu.cn/article/id/200504010 [4] 景宏君, 张斌. 黄土路基强度规律[J]. 交通运输工程学报, 2004, 4(2): 14-18. http://transport.chd.edu.cn/article/id/200402004Jing Hong-jun, Zhang Bin. Loess subgrade strength law[J]. Journal of Traffic and Transportation Engineering, 2004, 4(2): 14-18. (in Chinese) http://transport.chd.edu.cn/article/id/200402004 [5] 陈云敏, 贾宁, 陈仁朋. 桩承式路堤土拱效应分析[J]. 中国公路学报, 2004, 17(4): 1-6. doi: 10.3321/j.issn:1001-7372.2004.04.001Chen Yun-min, Jia Ning, Chen Ren-peng. Soil arch analysis of pile-supported embankments[J]. China Journal of Highway and Transport, 2004, 17(4): 1-6. (in Chinese) doi: 10.3321/j.issn:1001-7372.2004.04.001 [6] 曾卫兵, 张毅, 何挺继. 公路桥背回填压实试验[J]. 长安大学学报: 自然科学版, 2004, 24(1): 65-68. https://www.cnki.com.cn/Article/CJFDTOTAL-XAGL200401016.htmZeng Wei-bing, Zhang Yi, He Ting-ji. Test of backfill compacting on highway bridge back[J]. Journal of Chang'an University: Natural Science Edition, 2004, 24(1): 65-68. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-XAGL200401016.htm [7] 王吉利, 刘怡林, 栾茂田. 强夯法处理黄土路基检测方法试验研究[J]. 岩石力学与工程学报, 2004, 23(Supp1):4562-4 567. https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX2004S1065.htmWang Ji-li, Liu Yi-lin, Luan Mao-tian. Subsidence of bucket foundation under horizontal dynamic load[J]. Chinese Journal of Rock Mechanics and Engineering, 2004, 23(Supp1): 4 562-4 567. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX2004S1065.htm [8] 景宏君, 张斌. 黄土地区公路路基冲击压实试验[J]. 长安大学学报: 自然科学版, 2004, 24(1): 25-29. https://www.cnki.com.cn/Article/CJFDTOTAL-XAGL200401007.htmJing Hong-jun, Zhang Bin. Experiments of highway subgrade impact compaction in loess region[J]. Journal of Chang'an University: Natural Science Edition, 2004, 24(1): 25-29. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-XAGL200401007.htm [9] 钱鸿缙, 王继唐, 罗宇生. 湿陷性黄土地基[M]. 北京: 中国建筑工业出版社, 1985. [10] 沙庆林. 公路压实与压实标准[M]. 北京: 人民交通出版社, 2001. [11] 彭建兵, 陈立伟, 邓亚虹, 等. 车辆动荷作用下黄土暗穴对路基稳定性影响的数值分析[J]. 中国公路学报, 2006, 19(4): 17-22. https://www.cnki.com.cn/Article/CJFDTOTAL-ZGGL200604003.htmPeng Jian-bing, Chen Li-wei, Deng Ya-hong, et al. Numerical analysis of subgrade stability influenced by hidden holes in loess under dynamic load of vehicles[J]. China Journal of Highway and Transport, 2006, 19(4): 17-22. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-ZGGL200604003.htm [12] 沙爱民, 陈开圣. 压实黄土的湿陷性与微观结构的关系[J]. 长安大学学报: 自然科学版, 2006, 26(4): 1-4. https://www.cnki.com.cn/Article/CJFDTOTAL-XAGL200604000.htmSha Ai-min, Chen Kai-sheng. Relationship between collapsibility and microstructure of compacted loess[J]. Journal of Chang'an University: Natural Science Edition, 2006, 26(4): 1-4. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-XAGL200604000.htm [13] 朱彦鹏, 何永强. 湿陷性黄土地区倾斜建筑物的膨胀法纠偏机理及试验研究[J]. 兰州理工大学学报, 2006, 32(3): 108-111. https://www.cnki.com.cn/Article/CJFDTOTAL-GSGY200603030.htmZhu Yan-peng, He Yong-qiang. Rectification mechanism of expansion method for building inclination in area of collapsible loess and its experimental investigation[J]. Journal of Lanzhou University of Technology, 2006, 32(3): 108-111. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-GSGY200603030.htm [14] 邵生俊, 周飞飞, 宋春霞. 考虑黄土结构变化的地基增湿压缩变形分析[J]. 土木工程学报, 2006, 39(6): 94-99. https://www.cnki.com.cn/Article/CJFDTOTAL-TMGC200606017.htmShao Sheng-jun, Zhou Fei-fei, Song Chun-xia. Analysis of moistening and compression deformation of loess considering soil structure variations[J]. China Civil Engineering Journal, 2006, 39(6): 94-99. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-TMGC200606017.htm -
点击查看大图
图(12) / 表(2)
计量
- 文章访问数: 354
- HTML全文浏览量: 143
- PDF下载量: 266
- 被引次数: 0
