为进一步研究增压式真空预压对软土固结效果的影响,分别进行常规真空预压、通气和注气式真空预压固结淤泥质软土的室内模型试验,对比分析了3种处理方式后软土沉降量、含水率、抗剪强度、土颗粒形态、孔隙结构等宏微观特征差异。结果表明:相较于常规真空预压,通气和注气式真空预压土样沉降量分别增大了5.6%和12.3%;土体骨架颗粒大小更加均匀且排列密实,颗粒接触形式由点接触向面接触过渡,孔隙直径和数量也明显减小;增压式真空预压可以显著增大深部土样抗剪强度,使土体强度更加均匀,其中以注气式真空预压加固软土效果最好,土体抗剪强度增大了11.2 kPa。研究成果有助于揭示增压式真空预压对软土固结效果的影响机制。
Abstract
To investigate the impact of air-booster vacuum preloading on mucky clay consolidation, we conducted indoor model tests by employing conventional vacuum preloading, ventilated vacuum preloading, and air-injected vacuum preloading, respectively. Analyzing variations in soil settlement, water content, shear strength, soil particle morphology, and micro-pore structure revealed the following findings: in comparison to conventional vacuum preloading, soil settlement increased by approximately 5.6% and 12.3% with ventilated and air-injected vacuum preloading, respectively. Soil microstructure exhibited increased uniformity and density, transitioning from point contact to surface contact between particles. Additionally, both the diameter and quantity of soil pores evidently reduced. Ventilated and air-injected vacuum preloading significantly augmented the shear strength of deep soil, resulting in a more uniform soil matrix. Notably, air-injected vacuum preloading consistently demonstrated superior consolidation performance among the three methods, elevating deep soil shear strength by 11.2 kPa.
关键词
通气式真空预压 /
注气式真空预压 /
淤泥质软土 /
抗剪强度 /
土颗粒形态 /
孔隙结构
Key words
ventilated vacuum preloading /
air-injected vacuum preloading /
mucky clay /
shear strength /
soil particle morphology /
micro-pore structure
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1] 龚晓南. 地基处理手册[M]. 3版. 北京: 中国建筑工业出版社, 2008: 69-97. (GONG Xiao-nan. Handbook of Foundation Treatment[M]. Edition 3. Beijing: China Architecture & Building Press, 2008: 69-97. (in Chinese))
[2] 董志良, 张功新, 周 琦, 等. 天津滨海新区吹填造陆浅层超软土加固技术研发及应用[J]. 岩石力学与工程学报, 2011, 30(5): 1073-1080. (DONG Zhi-liang, ZHANG Gong-xin, ZHOU Qi, et al. Research and Application of Improvement Technology of Shallow ultra-soft Soil Formed by Hydraulic Reclamation in Tianjin Binhai New Area[J]. Chinese Journal of Rock Mechanics and Engineering, 2011, 30(5): 1073-1080.(in Chinese))
[3] LEI H, XU Y, LI X, et al. Effect of Polyacrylamide on Improvement of Dredger Fill with Vacuum Preloading Method[J]. Journal of Materials in Civil Engineering, 2019, 31(9): 1-8.
[4] 陈晓平. 海陆交互相沉积软土固结效应[J]. 岩土工程学报, 2011, 33(4): 520-528. (CHEN Xiao-ping. Consolidation Effect of Soft Soil in Interactive Marine and Terrestrial Deposit[J]. Chinese Journal of Geotechnical Engineering, 2011, 33(4): 520-528.(in Chinese))
[5] 姜 燕,杨光华,孙树楷,等.广州市南沙区软土物理力学指标统计分析[J].长江科学院院报,2019,36(9):99-103.(JIANG Yan,YANG Guang-hua,SUN Shu-kai,et al. Statistic Analysis of Physical and Mechanical Indexes of Soft Soil in Nansha of Guangzhou City[J]. Journal of Yangtze River Scientific Research Institute,2019,36(9):99-103.(in Chinese))
[6] 刘 伟, 陈凌伟, 张庆华, 等. 广州南沙区软土分布特征及工程性质[J]. 长江科学院院报, 2022, 39(1): 94-99. (LIU Wei, CHEN Ling-wei, ZHANG Qing-hua, et al. Distribution and Engineering Characteristics of Soft Clay in Nansha, Guangzhou[J]. Journal of Yangtze River Scientific Research Institute, 2022, 39(1): 94-99.(in Chinese))
[7] CAI Y, QIAO H, WANG J, et al. Experimental Tests on Effect of Deformed Prefabricated Vertical Drains in Dredged Soil on Consolidation via Vacuum Preloading[J]. Engineering Geology, 2017, 222: 10-19.
[8] 鲍树峰, 莫海鸿, 董志良, 等. 新近吹填淤泥地基负压传递特性及分布模式研究[J]. 岩土力学, 2014, 35(12): 3569-3576. (BAO Shu-feng, MO Hai-hong, DONG Zhi-liang, et al. Research on Transfer Properties and Distribution Model of Negative Pressure in Fresh Hydraulic Reclamation Muck Foundation[J]. Rock and Soil Mechanics, 2014, 35(12): 3569-3576.(in Chinese))
[9] 张凤海, 徐明江, 宋 兵. 基于十字板剪切试验的软基处理效果评价研究[J]. 广州建筑, 2019, 47(3): 19-23. (ZHANG Feng-hai, XU Ming-jiang, SONG Bing. Evaluation of Soft Foundation Treatment Based on Vane Shear Test[J]. Guangzhou Architecture, 2019, 47(3): 19-23.(in Chinese))
[10]蔡袁强. 吹填淤泥真空预压固结机理与排水体防淤堵处理技术[J]. 岩土工程学报, 2021, 43(2): 201-225. (CAI Yuan-qiang. Consolidation Mechanism of Vacuum Preloading for Dredged Slurry and Anti-clogging Method for Drains[J]. Chinese Journal of Geotechnical Engineering, 2021, 43(2): 201-225.(in Chinese))
[11]金亚伟,金亚君,蒋君南,等.增压真空预压固结处理软土地基/尾矿渣/湖泊淤泥的方法:中国,CN101418566B[P].2011-01-12.(JIN Ya-wei, JIN Ya-jun, JIANG Jun-nan, et al. Method for Processing Soft Land Base/Tail Slag/Lake Silt by Supercharging Preconsolidation at Vacuum: CN101418566B[P]. 2011-01-12.(in Chinese))
[12]SHEN Y, WANG H, TIAN Y, et al. A New Approach to Improve Soft Ground in a Railway Station Applying Air-boosted Vacuum Preloading[J]. Geotechnical Testing Journal, 2015, 38(4): 373-386.
[13]胡建斌, 潘 曼, 李维安, 等. 增压式真空预压法加固海相吹填土的现场试验研究[J]. 科学技术与工程, 2018, 18(9): 124-129. (HU Jian-bin, PAN Man, LI Wei-an, et al. Field Tests on Marine Dredger Fill Foundation by Air-boosted Vacuum Preloading[J]. Science Technology and Engineering, 2018, 18(9): 124-129.(in Chinese))
[14]WANG J, YANG Y, FU H, et al. Improving Consolidation of Dredged Slurry by Vacuum Preloading Using Prefabricated Vertical Drains (PVDS) with Varying Filter Pore Sizes[J]. Canadian Geotechnical Journal, 2020, 57(2): 294-303.
[15]朱 平, 孙立强, 闫澍旺, 等. 可控通气真空预压室内模型试验及其机制分析[J]. 岩石力学与工程学报, 2011, 30(增刊1): 3141-3148. (ZHU Ping, SUN Li-qiang, YAN Shu-wang, et al. Laboratory Model Test and Mechanism Analysis of Controlled Ventilation Vacuum Preloading[J]. Chinese Journal of Rock Mechanics and Engineering, 2011, 30(Supp.1): 3141-3148.(in Chinese))
[16]GB/T 50123—2019,土工试验方法标准[S]. 北京:中国计划出版社, 2019.(GB/T 50123-2019, Standard for Geotechnical Test Methods[S]. Beijing: China Planning Press, 2019. (in Chinese))
基金
国家自然科学基金项目(52308354);广州市建筑集团有限公司科技计划项目(2022-KJ017,2021-KJ006)
PDF(5813 KB)
