海上风电机组附近的浅层气突涌运移可能会诱发基础的失稳破坏,为了解决该潜在工程问题,通过开展模型试验和数值模拟,研究不同静荷载作用下,软黏土中气体运移路径的演化规律以及其对基础稳定性的影响。研究结果表明：静荷载的形式和基础与注气点的相对位置影响气体运移路径。当基础作用下压荷载时,气体朝靠近基础的方向运移,可能诱发基础失稳;而当作用上拔荷载时,气体朝远离基础的方向运移,从而不会威胁到基础的安全,且基础与注气点的相对位置越近,这种效应越显著。开展扩展有限元和Cohesive黏聚力单元相结合的应力-渗流耦合分析,进一步研究此种效应,以期为海上风电机组基础选址和设计提供参考依据。
Abstract
The shallow gas inrush close to offshore wind turbine foundation may cause instability of foundation. Little research has been conducted on this potential engineering problem. The experiments and numerical simulation were implemented to study the evolution law of gas migration in soft clay exposed to different static load and explore its influence on the stability of foundation. Results show that gas migration paths are influenced by load cases and the relative positions between the injection point and foundation. When foundation is exposed to compressive load, gas migrates towards the foundation and it may lead to instability. While it exposed to tension load, gas migrates far away from foundation and poses no threat to safety of bucket foundation. In addition, the closer the relative position between the injection point and foundation is, the more significant this influence is. By combining Extended finite element method (XFEM) and cohesive zone method, coupled hydro-mechanical analysis was conducted to study this influence, which can provide advice for the site selection and the design of offshore wind turbine foundation.
关键词
海上风电机组 /
数值模拟 /
气体运移 /
筒形基础 /
扩展有限元 /
最大主应力准则
Key words
offshore wind turbines /
numerical simulation /
gas migration /
bucket foundation /
extended finite element method /
maximum principal stress criterion
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参考文献
[1] 何奔, 罗金平, 李炜, 等. 海上风力机吸力桶基础循环特性离心机试验研究[J]. 太阳能学报, 2021, 42(9): 332-337.
HE B, LUO J P, LI W, et al.Investigation on cyclic response of suction bucket foundation supporting offshore wind turbine[J]. Acta energiae solaris sinica, 2021, 42(9): 332-337.
[2] 李萍, 杜军, 刘乐军, 等. 我国近海海底浅层气分布特征[J]. 中国地质灾害与防治学报, 2010, 21(1): 69-74.
LI P, DU J, LIU L J, et al.Characteristics of the shallow gas in Chinese offshore seabed[J]. The Chinese journal of geological hazard and control, 2010, 21(1): 69-74.
[3] 陈中轩, 来向华, 廖林燕, 等. 基于MIP-CPT技术的海底浅层气探测方法——以东海舟山海域为例[J]. 石油学报, 2016, 37(2): 207-213.
CHEN Z X, LAI X H, LIAO L Y, et al.Submarine shallow gas detection method based on MIP-CPT technology——taking Zhoushan sea area in the East China Sea as an example[J]. Journal of petroleum, 2016, 37(2): 207-213.
[4] JOHNSON B D, BOUDREAU B P, GARDINER B S, et al.Mechanical response of sediments to bubble growth[J]. Marine geology, 2002, 187(3-4): 347-363.
[5] BOUDREAU B P, ALGAR C, JOHNSON B D, et al.Bubble growth and rise in soft sediments[J]. Geology, 2005, 33(6): 517-520.
[6] SUN Z H, SANTAMARINA J C.Grain-displacive gas migration in fine-grained sediments[J]. Journal of geophysical research: solid earth, 2019, 124(3): 2274-2285.
[7] 王翔南, 李全明, 于玉贞, 等. 基于XFEM的土体水力劈裂模拟[J]. 岩土工程学报, 2020, 42(2): 390-397.
WANG X N, LI Q M, YU Y Z, et al.Hydraulic fracturing coupling model of rock mass based on extended finite element method[J]. Rock and soil mechanics, 2020, 42(2): 390-397.
[8] 孙峰, 逄铭玉, 张启汉, 等. 水平井压裂多裂缝同步扩展数值模拟[J]. 中南大学学报(自然科学版), 2017, 48(7): 1803-1808.
SUN F, PANG M Y, ZHANG Q H, et al.Numerical simulation of simultaneous propagation of multiple fractures in horizontal well[J]. Journal of Central South University (science and technology), 2017, 48(7): 1803-1808.
[9] 曾青冬, 姚军, 孙致学. 页岩气藏压裂缝网扩展数值模拟[J]. 力学学报, 2015, 47(6): 994-999.
ZENG Q D, YAO J, SUN Z X.Numerical modeling of fracture network propagation in shale reservoirs[J]. Chinese journal of theoretical and applied mechanics, 2015, 47(6): 994-999.
[10] 张广明, 刘勇, 刘建东, 等. 页岩储层体积压裂的地应力变化研究[J]. 力学学报, 2015, 47(6): 965-972.
ZHANG G M, LIU Y, LIU J D, et al.Research on the geo-stress change of shale reservoir volume fracturing[J]. Chinese journal of theoretical and applied mechanics, 2015, 47(6): 965-972.
[11] LIU J, ISKANDER M G.Modelling capacity of transparent soil[J]. Canadian geotechnical journal, 2010, 47(4): 451-460.
[12] 王海军, 周小日, 练继建. 船舶撞击下海上风电复合筒基础裂纹扩展研究[J]. 太阳能学报, 2020, 41(6): 47-52.
WANG H J, ZHOU X R, LIAN J J.Research on crack propagation of composite bucket foundation for offshore wind turbines impacted by ship[J]. Acta energiae solaris sinica, 2020, 41(6): 47-52.
[13] 贾善坡, 杨建平, 谭贤君, 等. 考虑渗流-应力耦合作用的层状盐岩界面裂缝扩展模型研究[J]. 中南大学学报(自然科学版), 2016, 47(1): 254-261.
JIA S P, YANG J P, TAN X J, et al.Analytic model for interface crack propagation of salt rock with interlayer under coupled mechanical-hydrological environment[J]. Journal of Central South University(science and technology), 2016, 47(1): 254-261.
[14] TURON A, CAMANHO P P, COSTA J, et al.A damage model for the simulation of delamination in advanced composites under variable-mode loading[J]. Mechanics of materials, 2006, 38(11): 1072-1089.
[15] JOHNSON B D, BARRY M A, BOUDREAU B P, et al.In situ tensile fracture toughness of surficial cohesive marine sediments[J]. Geo-marine letters, 2011, 32(1): 39-48.
[16] BOONE T J, INGRAFFEA A R.A numerical procedure for simulation of hydraulically driven fracture propagation in poroelastic media[J]. International journal for numerical and analytical methods in geomechanics, 1990, 14(1): 27-47.
[17] WANG X L, SHI F, LIU C, et al.Extended finite element simulation of fracture network propagation in formation containing frictional and cemented natural fractures[J]. Journal of natural gas science and engineering, 2018, 50: 309-324.
[18] MESRI G A.A reevaluation of Su(mob)=0.22σp'using laboratory shear tests[J]. Canadian geotechnical journal, 1989, 26(1): 162-164.
基金
国家国际科技合作专项（2015DFE7283）; 国家自然科学基金（52122906; 51779221; 51939010）; 浙江省自然科学基金（LHZ20E090001）
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