Analysis of the effect of air injection loading path on strengthening soft#br#
dredger fill by air-booster vacuum preloading method
LEI Huayang1，2，FANG Qingfeng1，LIU Jingjin1，2，WANG Lei1
(1. Department of Civil Engineering，Tianjin University，Tianjin 300354，China；2. Key Laboratory of Coast Civil Structure Safety of Ministry of Education，Tianjin University，Tianjin 300354，China)
Abstract：When air-booster vacuum preloading method is used to reinforce soft dredger fill，the reinforcement effect will be affected by air injection pressure and air injection time. Indoor model tests with different combinations of injection pressure and injection time were used to investigate the effect of the air injection loading path on the reinforcement of soft dredger fill. Four air injection loading paths were considered：constant pressure-constant time，constant pressure-variable time，variable pressure-constant time and variable pressure-variable time. The test results show that the reinforcement effect of air-booster vacuum preloading method is always better than that of conventional vacuum preloading method. And when the air injection loading path of variable pressure-variable time is adopted，the soil reinforcement effect is the best. Compared with the air injection loading path of constant pressure-constant time，the air injection loading path of variable pressure-variable time can lead to an increase in soil surface settlement by 9.25%，an increase in drainage by 9.35%，a decrease in average water content by 13.91% and an increase in average vane-shear strength by 20.59%. The gradual increase of air injection pressure and air injection time can effectively prevent the accumulation of clay particles to the prefabricated vertical drains(PVDs)，and increase the number of soil pores between PVDs and the booster board. The permeability of soil and the reinforcement effect of deep soil can be improved by using the loading path of variable pressure-variable time.
雷华阳1，2，方庆峰1，刘景锦1，2，王 磊1. 注气加载路径对增压式真空预压法加固吹填软土的效果分析[J]. 岩石力学与工程学报, 2023, 42(8): 2058-2067.
LEI Huayang1，2，FANG Qingfeng1，LIU Jingjin1，2，WANG Lei1. Analysis of the effect of air injection loading path on strengthening soft#br#
dredger fill by air-booster vacuum preloading method. , 2023, 42(8): 2058-2067.
[1] 金亚伟，金亚君，蒋君南，等. 增压式真空预压固结处理软土地基/尾矿渣/湖泊淤泥装置[P]. 中国：200820160080.7，2009–07–15.(JIN Yawei，JIN Yajun，JIANG Junnan，et al. Pressurized vacuum prepressure consolidation device for soft soil foundation/Tailings/lake sludge treatment[P]. China：200820160080.7，2009–07–15.(in Chinese))
[2] 王 军，蔡袁强，符洪涛，等. 新型防淤堵真空预压法室内与现场试验研究[J]. 岩石力学与工程学报，2014，33(6)：1 257–1 268. (WANG Jun，CAI Yuanqiang，FU Hongtao，et al. Laboratory and field test research of a new type of anti-blocking vacuum preloading method[J]. Chinese Journal of Rock Mechanics and Engineering，2014，33(6)：1 257–1 268.(in Chinese))
[3] CAI Y Q，XIE Z W，WANG J，et al. New approach of vacuum preloading with booster prefabricated vertical drains(PVDs) to improve deep marine clay strata[J]. NRC Research Press，2018，55(10)：1 359–1 371.
[4] 沈宇鹏，董淑海，王云超，等. 增压式真空预压两种固结解析解的对比分析[J]. 岩石力学与工程学报，2019，38(增1)：3 171–3 178. (SHEN Yupeng，DONG Shuhai，WANG Yunchao，et al. Comparative analysis between integral-transform solution and separate variable method for consolidation of the ground by air-boosted vacuum preloading[J]. Chinese Journal of Rock Mechanics and Engineering，2019，38(Supp.1)：3 171–3 178.(in Chinese))
[5] 沈宇鹏，冯瑞玲，余 江，等. 增压式真空预压处理软基的加固机制[J]. 吉林大学学报：地球科学版，2012，42(3)：792–797.(SHEN Yupeng，FENG Ruiling，YU Jiang，et al. Reinforcement of vacuum preloading with air pressure boosted for soft ground treatment[J]. Journal of Jilin University：Earth Science，2012，42(3)：792–797.(in Chinese))
[6] 丁海龙，郭志鹏，范开翼，等.增压式真空预压软基处置的对比试验研究[J]. 地下空间与工程学报，2015，11(增1)：16–18.(DING Haihong，GUO Zhipeng，FAN Kaiyi，et al. Comparative experiment on soft soil treatment by air-boosted vacuum preloading[J]. Chinese Journal of Underground Space and Engineering，2015，11(Supp.1)：16–18.(in Chinese))
[7] 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 Jianbin，PAN Man，LI Weian，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))
[8] 曾芳金，位会星，王 军，等. 深层增压式真空预压法处理软土地基室内模型试验[J]. 工业建筑，2014，44(7)：90–94.(ZENG Fangjin，WEI Huixing，WANG Jun，et al. laboratory model test of treating soft soil ground using deep air-boosted vacuum preloading[J]. Industrial Construction，2014，44(7)：90–94.(in Chinese))
[9] 谢志伟. 增压式真空预压法加固吹填淤泥试验研究[硕士学位论文][D]. 温州：温州大学，2017.(XIE Zhiwei. Experimental study on optimization design of air-boosted vacuum preloading for dredger fill[M. S. Thesis][D]. Wenzhou：Wenzhou University，2017.(in Chinese))
[10] KE S W，WANG P，HU X Q，et al. Effect of the pressurized duration on improving dredged slurry with air booster vacuum preloading[J]. Marine Georesources and Geotechnology，2019，38(8)：970–979.
[11] 史 吏，胡东东，蔡袁强，等. 增压式真空预压吹填淤泥孔压实时响应及加固机制初探[J]. 岩土力学，2020，41(1)：185–193.(SHI Li，HU Dongdong，CAI Yuanqiang，et al. Preliminary study of real-time pore water pressure response and reinforcement mechanism of air-booster vacuum preloading treated dredged slurry[J]. Rock and Soil Mechanics，2020，41(1)：185–193.(in Chinese))
[12] 雷华阳，王 鹏，刘 旭，等. 基于气体运移规律的增压式真空预压法加固机制分析[J]. 岩土力学，2021，42(4)：943–953.(LEI Huayang，WANG Peng，LIU Xu，et al. Influence of gas migration patterns on reinforcement of dredged slurry by air-booster vacuum preloading method[J]. Rock and Soil Mechanics，2021，42(4)：943–953.(in Chinese))
[13] LEI H Y，HU Y，ZHENG G，et al. Improved air-booster vacuum preloading method for newly dredged fills：Laboratory model study[J]. Marine Georesources and Geotechnology，2020，38(4)：439–510.
[14] 雷华阳，胡 垚，雷尚华，等. 增压式真空预压加固吹填超软土微观结构特征分析[J]. 岩土力学，2019，40(增1)：32–40.(LEI Huayang，HU Yao，LEI Shuanghua，et al. Analysis of microstructure characteristics of air-booster vacuum preloading for ultra-soft dredger fills[J]. Rock and Soil Mechanics，2019，40(Supp.1)：32–40.(in Chinese))
[15] 中华人民共和国国家标准编写组. GB/T 51064—2015 吹填土地基处理技术规范[S]. 北京：中国计划出版社，2015.(The National Standards Compilation Group of People?s Republic of China. GB/T 51064—2015 Technical code for ground treatment of hydraulic fill[S] Beijing：China Planning Publishing House，2015.(in Chinese))
[16] 中华人民共和国行业标准编写组. JGJ79—2012建筑地基处理技术规范[S]. 北京：中国建筑工业出版社，2012.(The Professional Standards Compilation Group of People?s Republic of China. JGJ79—2012 Technical code for ground treatment of buildings[S]. Beijing：China Architecture and Building Press，2012.(in Chinese))
[17] LEI H Y，LIU X，WANG P，et al. Experimental investigation of influence of air-boost pressure and duration on air-boost vacuum preloading consolidation[J]. International Journal of Geomechanics，2021，21(6)：04021088.
[18] ASAOKA A. Observational procedure of settlement prediction[J]. Soils and Foundations，1978，18(4)：87–101.
[19] 沈 杰. 高含水率疏浚泥真空预压室内模型试验研究[硕士学位论文][D]. 南京：东南大学，2015.(SHEN Jie. Laboratory model test of vacuum preloading on dredged clays at high initial water content[M. S. Thesis][D]. Nanjing：Southeast University，2015.(in Chinese))
[20] ZHOU Y，CHAI J C. Equivalent ‘smear’ effect due to non-uniform consolidation surrounding a PVD[J]. Géotechnique，2017，67(5)：410–419.
[21] 徐日庆，邓祎文，徐 波，等. 基于SEM图像的软土三维孔隙率计算及影响因素分析[J]. 岩石力学与工程学报，2015，34(7)：1 497– 1 502.(XU Riqing，DENG Yiwen，XU Bo，et al. Calculation of three-dimensional porosity of soft soil based on SEM image[J]. Chinese Journal of Rock Mechanics and Engineering，2015，34(7)：1 497–1 502.(in Chinese))
[22] 王 清，孙明乾，孙 铁，等. 不同处理方法下吹填土微观结构特征[J]. 同济大学学报：自然科学版，2013，41(9)：1 286–1 292. (WANG Qing，SUN Mingqian，SUN Tie，et al. Microstructure features of dredger fill by different solidified technologies[J]. Journal of Tongji University：Natural Science，2013，41(9)：1 286–1 292.(in Chinese))
[23] 侯超群，席 瑶，孙志彬，等. 基于IPP图像处理的膨胀土微观结构定量研究[J]. 水文地质工程地质，2019，46(2)：156–161.(HOU Chaoqun，XI Yao，SUN Zhibin，et al. A quantitative study of microstructure of expansive soil based on IPP image processing[J]. Hydrogeology and Engineering geology，2019，46(2)：156–161.(in Chinese))
[24] 方祥位，申春妮，李春海，等. 陕西蒲城黄土微观结构特征及定量分析[J]. 岩石力学与工程学报，2013，32(9)：1 917–1 925. (FANG Xiangwei，SHEN Chunni，LI Chunhai，et al. Quantitative analysis of microstructure characteristics of Pucheng loess in Shaanxi province[J]. Chinese Journal of Rock Mechanics and Engineering，2013，32(9)：1 917–1 925.(in Chinese))
2023, Vol. 42 
