According to the characteristic of clay aquiclude of overburden,the proper simulation materials and proportions of mixture for simulating the plastic clay aquiclude layers were developed,and the plastic similarity con...According to the characteristic of clay aquiclude of overburden,the proper simulation materials and proportions of mixture for simulating the plastic clay aquiclude layers were developed,and the plastic similarity conditions were setup.Thus,the simili- tude and simulation method in whole stress-strain was progressed.Furthermore,the simulation condition and material proportions in water reaction property and crack closing property were also put forward.Based on systematical tests,the development and distri- bution of mined cracks in roof and subsurface aquiclude was found and the stability of aquiclude was analyzed at all.At last,the key section and key index of aquclude stability was advanced.It is found that the movement of clay aquiclude follows the movement of the underlying bedrock layers.The basic caving mechanism of the overburden roof strata was also presented.展开更多
Based on mineral component and in-situ vane shear strength of deep-sea sediment, four kinds of simulative soils were prepared by mixing different bentonites with water in order to find the best simulative soil for the...Based on mineral component and in-situ vane shear strength of deep-sea sediment, four kinds of simulative soils were prepared by mixing different bentonites with water in order to find the best simulative soil for the deep-sea sediment collected from the Pacific C-C area. Shear creep characteristics of the simulative soil were studied by shear creep test and shear creep parameters were determined by Burgers creep model. Research results show that the shear creep curves of the simulative soil can be divided into transient creep, unstable creep and stable creep, where the unstable creep stage is very short due to its high water content. The shear creep parameters increase with compressive stress and change slightly or fluctuate to approach a constant value with shear stress, and thus average creep parameters under the same compressive stress are used as the creep parameters of the simulative soil. Traction of the deep-sea mining machine walking at a constant velocity can be calculated by the shear creep constitutive equation of the deep-sea simulative soil, which provides a theoretical basis for safe operation and optimal design of the deep-sea mining machine.展开更多
基金the National Natural Science Foundation of China(50375026)the Key Program of Science and Technology of the Ministry of Education of China(204183)the Program for New Century Excellent Talents in University of China(NCET-04-0971)
文摘According to the characteristic of clay aquiclude of overburden,the proper simulation materials and proportions of mixture for simulating the plastic clay aquiclude layers were developed,and the plastic similarity conditions were setup.Thus,the simili- tude and simulation method in whole stress-strain was progressed.Furthermore,the simulation condition and material proportions in water reaction property and crack closing property were also put forward.Based on systematical tests,the development and distri- bution of mined cracks in roof and subsurface aquiclude was found and the stability of aquiclude was analyzed at all.At last,the key section and key index of aquclude stability was advanced.It is found that the movement of clay aquiclude follows the movement of the underlying bedrock layers.The basic caving mechanism of the overburden roof strata was also presented.
基金Project(51274251)supported by the National Natural Science Foundation of China
文摘Based on mineral component and in-situ vane shear strength of deep-sea sediment, four kinds of simulative soils were prepared by mixing different bentonites with water in order to find the best simulative soil for the deep-sea sediment collected from the Pacific C-C area. Shear creep characteristics of the simulative soil were studied by shear creep test and shear creep parameters were determined by Burgers creep model. Research results show that the shear creep curves of the simulative soil can be divided into transient creep, unstable creep and stable creep, where the unstable creep stage is very short due to its high water content. The shear creep parameters increase with compressive stress and change slightly or fluctuate to approach a constant value with shear stress, and thus average creep parameters under the same compressive stress are used as the creep parameters of the simulative soil. Traction of the deep-sea mining machine walking at a constant velocity can be calculated by the shear creep constitutive equation of the deep-sea simulative soil, which provides a theoretical basis for safe operation and optimal design of the deep-sea mining machine.
