MECHANISM OF MUDFLAT SOFT CLAY STABILIZED BY MAGNSIA OXYSULFATE CEMENT AND ANALYSIS ON ITS MICRO-BEHAVIOR FOR OFFSHORE WIND FARM

Zhu Jianfeng; Yang Hao; Xu Riqing; Pan Binjie; Rao Chunyi

doi:10.19912/j.0254-0096.tynxb.2020-1252

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Acta Energiae Solaris Sinica ›› 2022, Vol. 43 ›› Issue (7) : 276-283. DOI: 10.19912/j.0254-0096.tynxb.2020-1252

MECHANISM OF MUDFLAT SOFT CLAY STABILIZED BY MAGNSIA OXYSULFATE CEMENT AND ANALYSIS ON ITS MICRO-BEHAVIOR FOR OFFSHORE WIND FARM

Zhu Jianfeng¹, Yang Hao¹, Xu Riqing², Pan Binjie³, Rao Chunyi^3,4

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Abstract

The mudflat soft clay with high soil moisture and low compression modulus should be enhanced before the practical foundation construction of offshore wind farm. To investigate the stabilized mechanism and micro behavior of mudflat soft clay solidified by the magnesia oxysulfate cement, the X-ray diffraction （XRD） tests were conducted to determine the micro-ingredients of the mudflat soft clay solidified by the magnesia oxysulfate cement composite curing agent. A series of scanning electron microscope （SEM） tests were conducted on the solidified soil with different soil moistures（w）, curing agent dosages （Wg） and ages （T）. Then, the effects of w and Wg and T on the micro-void, micro-morphology and the contact area ratio （RCA） of the solidified soil were investigated by using Image Processing. It was found that the solidified soil was mainly constitutive of quartz, 5·1·7 phase, dolomite, pyrophyllite, M-F-A-S phase and a little of CaO and MgO. The stabilization of solidified soil is mainly due to the hydration and hydrolysis reaction of the modified magnesia cement, ion exchange and filling effect and the carbonation. The solidified soil mainly covers three types of micro-void： gelling and contact and skeleton, and it also contain three types of solid particles： foliated, granulous and clotted. The smaller the initial soil moisture, the larger the amount of curing agent and the longer the age, the greater the RCA and the macro-physical parameters （initial tangent modulus, Ei, and shear strength parameters, c and φ）of the solidified soil. Finally, the functional relationships between Ei, c, φ and RCA were established.

Key words

offshore wind farms / clay / mudflat / soil moisture / magnesium oxysulfate cement / microstructure

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Zhu Jianfeng, Yang Hao, Xu Riqing, Pan Binjie, Rao Chunyi. MECHANISM OF MUDFLAT SOFT CLAY STABILIZED BY MAGNSIA OXYSULFATE CEMENT AND ANALYSIS ON ITS MICRO-BEHAVIOR FOR OFFSHORE WIND FARM[J]. Acta Energiae Solaris Sinica. 2022, 43(7): 276-283 https://doi.org/10.19912/j.0254-0096.tynxb.2020-1252

References

[1] 翟恩地, 徐海滨, 郭胜山, 等. 响水海上风电钢管桩基础水平承载特性对比研究[J]. 太阳能学报, 2019, 40(3): 681-686.
ZHAI E D, XU H B, GUO S S, et al.Comparative study on horizontal bearing capacity of steel pipe pile for xiangshui offshore wind farm[J]. Acta energiae solaris sinica, 2019, 40(3): 681-686.
[2] 张鸿, 金书成, 黎冰, 等. 海上风电吸力式沉箱基础沉贯试验研究[J]. 太阳能学报, 2016, 37(11): 2827-2834.
ZHANG H, JIN S C, LI B, et al.Experimental study on the foundation of offshore wind power suction caisson foundation[J]. Acta energiae solaris sinica, 2016, 37(11): 2827-2834.
[3] 徐日庆, 王旭, 文嘉毅, 等. 浅层淤泥质土固化剂[J]. 上海交通大学学报, 2019, 53(7): 805-810.
XU R Q, WANG X, WEN J Y, et al.Curing agent for shallow mucky soil[J]. Journal of Shanghai Jiao Tong University, 2019, 53(7): 805-810.
[4] 饶春义, 朱剑锋, 潘斌杰, 等. 基于扰动状态概念理论的固化淤泥一维压缩模型[J]. 岩土工程学报, 2019, 41(增1): 173-176.
RAO C Y, ZHU J F, PAN B J, et al.One-dimensional compression model for solidified silt based on theory of disturbed state concept[J]. Chinese journal of geotechnical engineering, 2019, 41(S1): 173-176.
[5] 朱剑锋, 饶春义, 庹秋水, 等. 硫氧镁水泥复合固化剂加固淤泥质土的试验研究[J]. 岩石力学与工程学报, 2019, 38(增1): 3206-3214.
ZHU J F, RAO C Y, TUO Q S, et al.Experimental study on the properties of the organic soil solidified by the composite magnesium oxysulfate cement-curing agent[J]. Chinese journal of rock mechanics and engineering, 2019, 38(S1): 3206-3214.
[6] 朱剑锋, 庹秋水, 邓温妮, 等. 镁质水泥复合固化剂固化有机质土的抗压强度模型[J]. 浙江大学学报(工学版), 2019, 53(11): 2168-2174.
ZHU J F, TUO Q S, DENG W N, et al.Model of compressive strength of cured organic soil solidified by magnesium cement complex curing agent[J]. Joural of Zhejiang University (engineering science), 2019, 53(11): 2168-2174.
[7] 王清, 陈慧娥, 蔡可易. 水泥土微观结构特征的定量评价[J]. 岩土力学, 2003, 24(增1): 12-16.
WANG Q, CHEN H E, CAI K Y.Quantitative evaluation of microstructure features of soil contained some cement[J]. Rock and soil mechanics, 2003, 24(S1): 12-16.
[8] 黄雨, 周子舟, 柏炯, 等. 石膏添加剂对水泥土搅拌法加固软土地基效果[J]. 岩土工程学报, 2010, 32(8): 1179-1183.
HUANG Y, ZHOU Z Z, BAI J, et al.Micro-experiments on a soft ground improved by cement-mixed soils with gypsum additive[J]. Chinese journal of geotechnical engineering, 2010, 32(8): 1179-1183.
[9] 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): 1497-1502.
XU R Q, DENG Y W, XU B, 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): 1497-1502.
[10] 陆建阳. 宁波淤泥质土固化研究及微观定量研究[D]. 杭州: 浙江大学, 2016.
LU J Y.Solidification research and microscopic quantitative study of Ningbo mucky soil[D]. Hangzhou: Zhejiang University, 2016.
[11] 中华人民共和国水利部. 土工试验规程(SL 237—1999).[S]. 北京: 中国水利水电出版社, 1999.
The Ministry of Water Resources of the People’s Republic of China. Specification of soil test(SL 237—1999)[S]. Beijing: China Water & Power Press, 1999.
[12] 刘用海. 宁波软土工程特性及其本构模型应用研究[D]. 杭州: 浙江大学, 2008.
LIU Y H.Study on engineering property and application of constitutive model for Ningbo soft clay[D]. Hangzhou: Zhejiang University, 2008.
[13] URWONGSE L, SORRELL C A.Phase relationships in magnesium oxysulfate cements[J]. Journal of the American Ceramic Society, 1980, 63(9-10): 523.
[14] XU B W, MA H Y, HU C L, et al.Influence of curing regimes on mechanical properties of magnesium oxychloride cement-based composites[J]. Construction and building materials, 2016, 102: 613-619.
[15] BA M F, XUE T, HE Z M, et al.Carbonation of magnesium oxysulfate cement and its influence on mechanical performance[J]. Construction and building materials, 2019, 223, 1030-1037.
[16] SULEA R, SIGALAS I.Effect of temperature on mullite synthesis from attrition-milled pyrophyllite and α-alumina by spark plasma sintering[J]. Applied clay science, 2018, 162: 288-296.
[17] 朱剑锋,徐日庆,罗战友,等. 考虑3种因素影响的硫氧镁水泥固化土修正邓肯-张模型[J]. 中南大学学报(自然科学版): 2020, 51(7): 1989-2001.
ZHU J F, XU R Q, LUO Z Y, et al.Modified Duncan-Chang constitutive model for soft soil stabilized by magnesium oxysulfate cement considering the effect of three factor[J]. Journal of Central South University(natural science edition), 2020, 51(7): 1989-2001.
[18] 徐日庆, 张俊, 朱剑锋, 等. 考虑扰动影响的修正Duncan-Chang模型[J]. 浙江大学学报(工学版), 2012, 46(1): 1-7.
XU R Q, ZHANG J, ZHU J F, et al.Modified Duncan-Chang model considering disturbance[J]. Joural of Zhejiang University(engineering science edition), 2012, 46(1): 1-7.