Using a circular incremental step load and unload method, a set of rheological experiments were performed to study the viscoelasto-plastic properties of amphibolite in Jinchuan No.2 diggings under different environmen...Using a circular incremental step load and unload method, a set of rheological experiments were performed to study the viscoelasto-plastic properties of amphibolite in Jinchuan No.2 diggings under different environments. Based on the scientific analysis on rheological experimental data, the viscoelasto-plastic properties of amphibolite under different environments were studied. The results show that the instantaneous elastic modulus and viscoplastic properties of amphibolite are affected little, the viscoelastic properties of amphibolite are significantly affected. Based on the experimental results and characteristics of recovered rock specimen, a generalized Kelvin model was chosen to simulate rheological properties of amphibolites and key parameters were obtained. It is found that the creep deformation modulus E1 is significantly influenced by the water, while the instant elastic modulus E2 is not significantly affected. The discreteness of the viscosity coefficient η is large, the influence of water on η is not clear and needs to be further studied.展开更多
Rock mass unloading is an important rock engineering problem because unloading may impact the stability of a rock mass slope. Based on hydroelectric engineering principles, this study focuses on the classification of ...Rock mass unloading is an important rock engineering problem because unloading may impact the stability of a rock mass slope. Based on hydroelectric engineering principles, this study focuses on the classification of unloading zones to reflect the rock mass structure characteristics. Geological background and slope structure of the study region were considered to investigate the distribution and deformation of the unloading process. Quantitative indices were classified according to the formation mechanisms and the geological exhibition of unloading zones. The P-wave velocity(V_P), the ratio of the wave velocity(V_p) the ratio of the test P-wave velocity along the adit depth to the P-wave velocity of intact rock, the sum of joint openings every 2 meters(S_t), and the density of open joints(D_t) were calculated as quantitative indices for the rock mass unloading zone. The characteristics of the unloading zone of rock mass slopes at the dam site were successfully determined. The method of combining qualitative data with quantitative indices was found to be effective for the classification of slope unloading zones.展开更多
Floating production storage and offloading （FPSO） units increasingly represent a practical and economic means for deep-water oil extraction and production. Systems thinking gives a unique opporamity to seek a balanc...Floating production storage and offloading （FPSO） units increasingly represent a practical and economic means for deep-water oil extraction and production. Systems thinking gives a unique opporamity to seek a balance between FPSO technical performance（s）, with whole-cost; stakeholder decision-making is charged to align different fit-for-use design specification options＇ that address technical-motion（s）, with respective life-cycle cost analyses （LCCA）. Soft system methodology allows situation based analyses over set periods-of-time by diagnosing the problem-at-hand; namely, assessing the antecedents of life-cycle cost relative to FPSO sub- component design alternatives. Alternative mooring- component comparisons for either new-build hulls or refurbished hulls represent an initial necessary considera- tion to facilitate extraction, production and storage of deep- water oil reserves. Coupled dynamic analysis has been performed to generate FPSO motion in six degrees of freedom using SESAM DeepC, while life-cycle cost analysis （LCAA） studies give net-present-value comparsons reflective of market conditions. A parametric study has been conducted by varying wave heights from 4 - 8 m to understand FPSO motion behavior in the presence of wind and current, as well as comparing the motions of turreted versus spread mooring design alternatives. LCCA data has been generated to compare the cost of such different mooring options/hull conditions over 10 and 25- year periods. Systems thinking has been used to explain the interaction of problem variables; resultantly this paper is able to identify explicit factors affecting the choice of FPSO configurations in terms of motion and whole-cost, toward assisting significantly with the front-end engineering design （FEED） phase of fit-for-purpose configured FPSOs, in waters off Malaysia and Australia.展开更多
基金Project (10972238) supported by the National Natural Science Foundation of ChinaProject (2009bsxt061) supported by the Thesis Innovation Funds for the Central South University, ChinaProject (2009) supported by Hunan Administration of Work Safety Fund, China
文摘Using a circular incremental step load and unload method, a set of rheological experiments were performed to study the viscoelasto-plastic properties of amphibolite in Jinchuan No.2 diggings under different environments. Based on the scientific analysis on rheological experimental data, the viscoelasto-plastic properties of amphibolite under different environments were studied. The results show that the instantaneous elastic modulus and viscoplastic properties of amphibolite are affected little, the viscoelastic properties of amphibolite are significantly affected. Based on the experimental results and characteristics of recovered rock specimen, a generalized Kelvin model was chosen to simulate rheological properties of amphibolites and key parameters were obtained. It is found that the creep deformation modulus E1 is significantly influenced by the water, while the instant elastic modulus E2 is not significantly affected. The discreteness of the viscosity coefficient η is large, the influence of water on η is not clear and needs to be further studied.
基金supported by the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (Grant No. 41521002)the National ScienceTechnology Support Program of China (Grant No. 2015BAK09B01)the Key Project of theNational Natural Science Foundation of China (Grant No. 41130745)
文摘Rock mass unloading is an important rock engineering problem because unloading may impact the stability of a rock mass slope. Based on hydroelectric engineering principles, this study focuses on the classification of unloading zones to reflect the rock mass structure characteristics. Geological background and slope structure of the study region were considered to investigate the distribution and deformation of the unloading process. Quantitative indices were classified according to the formation mechanisms and the geological exhibition of unloading zones. The P-wave velocity(V_P), the ratio of the wave velocity(V_p) the ratio of the test P-wave velocity along the adit depth to the P-wave velocity of intact rock, the sum of joint openings every 2 meters(S_t), and the density of open joints(D_t) were calculated as quantitative indices for the rock mass unloading zone. The characteristics of the unloading zone of rock mass slopes at the dam site were successfully determined. The method of combining qualitative data with quantitative indices was found to be effective for the classification of slope unloading zones.
文摘Floating production storage and offloading （FPSO） units increasingly represent a practical and economic means for deep-water oil extraction and production. Systems thinking gives a unique opporamity to seek a balance between FPSO technical performance（s）, with whole-cost; stakeholder decision-making is charged to align different fit-for-use design specification options＇ that address technical-motion（s）, with respective life-cycle cost analyses （LCCA）. Soft system methodology allows situation based analyses over set periods-of-time by diagnosing the problem-at-hand; namely, assessing the antecedents of life-cycle cost relative to FPSO sub- component design alternatives. Alternative mooring- component comparisons for either new-build hulls or refurbished hulls represent an initial necessary considera- tion to facilitate extraction, production and storage of deep- water oil reserves. Coupled dynamic analysis has been performed to generate FPSO motion in six degrees of freedom using SESAM DeepC, while life-cycle cost analysis （LCAA） studies give net-present-value comparsons reflective of market conditions. A parametric study has been conducted by varying wave heights from 4 - 8 m to understand FPSO motion behavior in the presence of wind and current, as well as comparing the motions of turreted versus spread mooring design alternatives. LCCA data has been generated to compare the cost of such different mooring options/hull conditions over 10 and 25- year periods. Systems thinking has been used to explain the interaction of problem variables; resultantly this paper is able to identify explicit factors affecting the choice of FPSO configurations in terms of motion and whole-cost, toward assisting significantly with the front-end engineering design （FEED） phase of fit-for-purpose configured FPSOs, in waters off Malaysia and Australia.
