1. Faculty of Architectural, Civil Engineering and Environment, Ningbo University, Ningbo 315211, China 2. School of Civil Engineering and Architecture, Zhejiang University of Science and Technology, Hangzhou 310023,China 3. Bridge Branch Zhejiang Provincial Transportation Engineering Construction Group Co. Ltd, Hangzhou 310051, China 4. School of Civil Engineering, Southeast University, Nanjing 211189, China
In order to provide evaluation basis for the solidification effect of cured organic soil solidified by the magnesium cement complex curing agent in practical engineering, the unconfined compressive strength of the magnesium-cement cured soil (TZ18 cured soil) was taken as the evaluation index, and the influences of the mass fraction of organic matter, water and curing agent and the age on the unconfined compressive strength were investigated. Results showed that the unconfined compressive strength of the TZ18 cured soil decreased in quadratic function with the increase of organic matter mass fraction and reduced in power function with the increase of water mass fraction, whereas increased in power function with the increase of cured agent mass fraction and enhanced in natural logarithm function with the growth of age. Based on the above tested results, a forecast model of the comprehensive compressive strength of TZ18 cured organic soil was developed. Example analysis indicated that the proposed model can predict the unconfined compressive strength of TZ18 cured soil at any mass fraction of organic matter, water and curing agent as well as age.
Jian-feng ZHU,Qiu-shui TUO,Wen-ni DENG,Chun-yi RAO,Hao-xu LIU. Model of compressive strength of cured organic soil solidified by magnesium cement complex curing agent. Journal of ZheJiang University (Engineering Science), 2019, 53(11): 2168-2174.
Tab.1Physical and mechanical properties of soil sample
材料名称
分子/结构式
规格
生产厂家
1）注：AR为分析纯试剂（analytical reagent）
腐殖酸
?
农业级
江西萍乡红土地
七水硫酸镁
MgSO4·7H2O
农业级
广州林国化肥
轻烧氧化镁
MgO
工业级
辽宁海城菱镁矿
柠檬酸
C6H8O7
AR1）
上海国药集团
水玻璃
NaSiO3
AR
天津鼎盛鑫化工
熟料
?
工业级
发电厂
硅灰
?
工业级
发电厂
Tab.2Test raw materials for unconfined compressive strength
Fig.2Preparation of artificial organic soil and TZ18 cured soil
组别
影响因素
各因素配比方案
T
M-0
基准配比
wC=15%；wO=6%；wW=60%
7 d
M-1
wC
12%、15%、18%、20%
7 d
M-2
wO
0%、3%、6%、9%
7 d
M-3
wW
50%、60%、70%、80%
7 d
M-4
T
7 d、14 d、28 d、60 d
?
Tab.3Test program of unconfined compressive strength of TZ18 cured soil
Fig.3Variation of unconfined compressive strength of TZ18 cured soil (7 d) along with mass fraction of humic acid
Fig.4Variation of unconfined compressive strength of TZ18 cured soil (7 d) along with mass fraction of water
Fig.5Variation of unconfined compressive strength of TZ18 cured soil (7 d) along with mass fraction of curing agent
Fig.6Variation of unconfined compressive strength of TZ18 cured soil along with age
Fig.7Relationship between normalized unconfined compressive strength of TZ18 cured soil (7 d) and total cement-water ratio
Fig.8Relationship between normalized mass fraction of humic acid and parameter A0
Fig.9Relationship between normalized unconfined compressive strength of TZ18 cured soil and age
层号
土层名称
wW/%
γ/（kN·m–3）
e
wp/%
wL/%
Es1-2/MPa
φ/（°）
c/kPa
wO/%
①3
淤泥质土
68.4
17.2
1.332
27.0
45.1
2.2
10.0
14.0
6.90
③1a
淤泥质土
56.9
17.5
1.143
21.8
36.3
2.7
10.5
14.0
5.47
④1
淤泥质土
41.1
17.9
1.003
20.5
32.7
2.8
11.5
17.0
3.97
Tab.4Engineering indicators of test soil samples
组别
试验用土所在层号
实测值/kPa
理论值/kPa
相对误差/%
E-1
①3
706.2
736.87
4.34
E-2
③1a
950.9
971.75
2.19
E-3
④1
1 563.2
1 522.37
–2.60
Tab.5Comparison between measured and theoretical unconfined compressive strength (7 d) of TZ18 cured soil
[1]
丁建文, 张帅, 洪振舜, 等 水泥-磷石膏双掺固化处理高含水率疏浚淤泥试验研究[J]. 岩土力学, 2010, 31 (9): 2817- 2822 DING Jian-wen, ZHANG Shuai, HONG Zhen-shun, et al Experimental study of solidification of dredged clays with high water content by adding cement and phosphogypsum synchronously[J]. Rock and Soil Mechanics, 2010, 31 (9): 2817- 2822
doi: 10.3969/j.issn.1000-7598.2010.09.021
[2]
徐日庆, 郭印, 刘增永 人工制备有机质固化土力学特性试验研究[J]. 浙江大学学报: 工学版, 2007, 41 (1): 109- 113 XU Ri-qing, GUO Yin, LIU Zeng-yong Experimental study on mechanical properties of stabilized artificial organic soil[J]. Journal of Zhejiang University: Engineering Science, 2007, 41 (1): 109- 113
[3]
庹秋水, 朱剑锋, 饶春义 固化有机质土的抗剪强度试验研究[J]. 泥沙研究, 2017, 42 (5): 70- 74 TUO Qiu-shui, ZHU Jian-feng, RAO Chun-yi Experimental study on shear strength of stabilized organic soil[J]. Journal of Sediment Research, 2017, 42 (5): 70- 74
[4]
TREMBLAY H, DUCHESNE J, LOCAT J, et al Influence of the nature of organic compounds on fine soil stabilization with cement[J]. Canadian Geotechnical Journal, 2002, 39 (3): 535- 546
doi: 10.1139/t02-002
[5]
郭印, 徐日庆, 邵允铖 淤泥质土的固化机理研究[J]. 浙江大学学报: 工学版, 2008, 42 (6): 1071- 1075 GUO Yin, XU Ri-qing, SHAO Yun-cheng Study on mechanism of muddy soil stabilization[J]. Journal of Zhejiang University: Engineering Science, 2008, 42 (6): 1071- 1075
[6]
朱伟, 曾科林, 张春雷 淤泥固化处理中有机物成分的影响[J]. 岩土力学, 2008, 29 (1): 33- 36 ZHU Wei, ZENG Ke-lin, ZHANG Chun-lei Influence of organic matter component on solidification of dredged sediment[J]. Rock and Soil Mechanics, 2008, 29 (1): 33- 36
doi: 10.3969/j.issn.1000-7598.2008.01.007
[7]
HARVEY O R, HARRIS J P, HERBERT B E Natural organic matter and the formation of calcium-silicate-hydrates in lime-stabilized smectites: a thermal analysis study[J]. Thermochimica Acta, 2010, 505 (1/2): 106- 113
[8]
程福周, 雷学文, 孟庆山, 等 水泥-水玻璃固化东湖淤泥的室内试验研究[J]. 人民长江, 2013, 44 (24): 45- 48 CHENG Fu-zhou, LEI Xue-wen, MENG Qing-shan, et al Indoor experiment study on solidification of lake silt by cement-sodium silicate[J]. Yangtze River, 2013, 44 (24): 45- 48
doi: 10.3969/j.issn.1001-4179.2013.24.013
李兆恒. MgO-SiO2-H2O胶凝体系的反应机制及应用研究[D]. 广州: 华南理工大学, 2015. LI Zhao-heng. Reaction mechanisms and application study of MgO-SiO2-H2O cementitious system [D]. Guangzhou: South China University of Technology, 2015.
[11]
钱春香, 王安辉, 王欣 微生物灌浆加固土体研究进展[J]. 岩土力学, 2015, 36 (6): 1538- 1548 QIAN Chun-xiang, WANG An-hui, WANG Xin Advances of soil improvement with bio-grouting[J]. Rock and Soil Mechanics, 2015, 36 (6): 1538- 1548
[12]
庹秋水. 镁质水泥复合固化剂加固淤泥质土的试验研究[D]. 宁波: 宁波大学, 2018. TUO Qiu-shui. Experimental study on curing muddy soil with magnesium cement composite curing agent [D]. Ningbo: Ningbo University, 2018.
[13]
汤怡新, 刘汉龙, 朱伟 水泥固化土工程特性试验研究[J]. 岩土工程学报, 2000, 22 (5): 549- 554 TANG Yi-xin, LIU Han-long, ZHU Wei Study on engineering properties of cement-stabilized soil[J]. Chinese Journal of Geotechnical Engineering, 2000, 22 (5): 549- 554
doi: 10.3321/j.issn:1000-4548.2000.05.008
[14]
LEE F H, LEE Y, CHEW S H, et al Strength and modulus of marine clay-cement mixes[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2005, 131 (2): 178- 186
doi: 10.1061/(ASCE)1090-0241(2005)131:2(178)
[15]
刘汉龙, 董金梅, 周云东, 等 聚苯乙烯轻质混合土物理力学特性的影响因素[J]. 岩土力学, 2005, 26 (3): 445- 449 LIU Han-long, DONG Jin-mei, ZHOU Yun-dong, et al Factors influencing on physico-mechanical properties of the light soil mixed polystyrene[J]. Rock and Soil Mechanics, 2005, 26 (3): 445- 449
doi: 10.3969/j.issn.1000-7598.2005.03.022
[16]
储诚富, 洪振舜, 刘松玉, 等 用似水灰比对水泥土无侧限抗压强度的预测[J]. 岩土力学, 2005, 26 (4): 645- 649 CHU Cheng-fu, HONG Zhen-shun, LIU Song-yu, et al Prediction of unconfined compressive strength of cemented soils with quasi-water-cement ratio[J]. Rock and Soil Mechanics, 2005, 26 (4): 645- 649
doi: 10.3969/j.issn.1000-7598.2005.04.030
[17]
张铁军, 洪振舜, 邓东升, 等 水泥固化粉质土的无侧限抗压强度预测[J]. 东南大学学报: 自然科学版, 2008, 38 (5): 839- 843 ZHANG Tie-jun, HONG Zhen-shun, DENG Dong-sheng, et al Predication method of unconfined compression strength for cemented silty soils[J]. Journal of Southeast University: Natural Science Edition, 2008, 38 (5): 839- 843
[18]
徐日庆, 李俊虎, 蔡承晟, 等 用固化剂GX08加固杭州海湖相软土的强度特性研究[J]. 岩土力学, 2014, 35 (6): 1528- 1533 XU Ri-qing, LI Jun-hu, CAI Cheng-sheng, et al Study of strength characteristics of stabilized soil by using stabilizing agent GX08 treating marine and lacustrine soft soil in Hangzhou[J]. Rock and Soil Mechanics, 2014, 35 (6): 1528- 1533
[19]
蔡光华. 活性氧化镁碳化加固软弱土的试验与应用研究[D]. 南京: 东南大学, 2017. CAI Guang-hua. Experimental and application studies on soft soil carbonated and stabilized by reactive magnesia [D]. Nanjing: Southeast University, 2017.
