摘要
可燃冰分解会导致含可燃冰砂土-开采井界面承载力降低,产生错位、滑动等非连续性变形,直接影响开采井的稳定性。为研究分解条件下含可燃冰砂土-开采井界面弱化规律,基于研制的低温-高压可燃冰生成及三轴测试设备,开展了分解条件下含可燃冰砂土-开采井界面剪切试验,构建了考虑分解效应的含可燃冰砂土-开采井界面统计损伤模型。研究结果表明,可燃冰分解前界面呈应变软化状态,界面抗剪强度和剪胀性随饱和度增加而增大;分解后界面呈应变硬化状态,界面强度亦随饱和度的增加而增大,但剪胀性受其影响略小。与分解前相比,分解后界面抗剪强度、黏聚力、剪胀性等均降低,呈显著的弱化特性。由此考虑界面微元强度服从MohrCoulomb屈服准则和双参数Weibull分布,构建了可较好描述分解引起的含可燃冰砂土-开采井界面变形破坏的界面统计损伤模型,分析模型中的参数m和F_(0)与可燃冰饱和度、有效围压和分解条件的关系。相关成果可促进可燃冰勘探开发基础理论和关键技术研究。
The dissociation of gas hydrate leads to the reduction of the bearing capacity of the interface between gas hydrate-bearing soil and mining well,resulting in discontinuous deformation such as dislocation and sliding,which directly affects the stability of the mining well.In order to study the weakening law of gas hydrate-bearing soil-mining well interface under dissociation conditions,based on the developed low-temperature and high-pressure gas hydrate generation and triaxial test equipment,shear tests of gas hydrate-bearing sand-mining well interface under dissociation conditions are carried out,and the statistical damage model of gas hydrate-bearing sand-mining well interface considering dissociation effect is constructed.As a result,the interface is in strain softening state before gas hydrate dissociation,and the shear strength and dilatancy increase with the increase of saturation.The interface is in strain hardening state after dissociation,and the shear strength increases with the increase of saturation,but the dilatancy is slightly affected by it.In addition,comparing with before dissociation,the shear strength,cohesion and dilatancy of the interface decreased after dissociation,showing significant weakening characteristics.Therefore,considering the strength of the interface finite micro cells obeys Mohr-Coulomb strength criterion and double-parameter Weibull random distribution,the interface statistical damage model which can better simulate the failure of gas hydrate-bearing sand-mining well interface caused by dissociation is established,the relationships of the parameters m and F_(0)in the model with gas hydrate saturation,effective confining pressure and dissociation are analyzed.The relevant results can promote the research on the basic theory and key technology of gas hydrate exploration and development.
作者
张玉
陶子卓
栾雅琳
狄圣杰
林亮
ZHANG Yu;TAO Zizhuo;LUAN Yalin;DI Shengjie;LIN Liang(College of Pipeline and Civil Engineering,China University of Petroleum(East China),Qingdao,Shandong 266580,China;Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines,Northeastern University,Shenyang,Liaoning 110819,China;PowerChina Northwest Engineering Corporation Limited,Xi'an,Shaanxi 710065,China;Qingdao Fusion Bridgehead Development Co.,Ltd.,Qingdao,Shandong 266500,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2024年第S02期3988-3999,共12页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(51890914,52179119)
山东省自然科学基金资助项目(ZR2019MEE001)
关键词
土力学
可燃冰
分解
含可燃冰砂土-开采井界面
界面弱化
统计损伤模型
soil mechanics
gas hydrate
dissociation
gas hydrate-bearing sand-mining well interface
interface weakening
statistical damage model
