A new method was proposed to predict the limited compaction grouting pressure for the soft soils. Theoretical basis of the method considered the conical shear failure above the grout bulb. Using the Mohr-Coulomb yield...A new method was proposed to predict the limited compaction grouting pressure for the soft soils. Theoretical basis of the method considered the conical shear failure above the grout bulb. Using the Mohr-Coulomb yield criterion as the initial yield function, the limited compaction grouting pressure was determined, according to the softening elastic-plastic model based on the conventional triaxial compression tests to simulate the strain softening soils. The small strain in the elastic zone and large stain in the plastic zone and the rational yield function for the strain softening phase stage, the analytical solutions to the compaction grouting pressure were presented. The results indicate reasonable agreement and show a good potential of the proposed method for rationally optimizing the design of compaction grouting operations.展开更多
In order to study the application of gyratory compaction molding method in emulsified asphalt cold recycled mixture and optimize the relevant technical parameters, the study was carried out according to splitting stre...In order to study the application of gyratory compaction molding method in emulsified asphalt cold recycled mixture and optimize the relevant technical parameters, the study was carried out according to splitting strength, stability and water stability test;the design of the experiment involved changing gyration number, emulsified asphalt and water content, molded specimen temperature and other factors to analyze the volume parameters, mechanical properties and water stability. The results show that both the maximum dry density and dry and wet splitting strength ratio(DWSSR) of emulsified asphalt cold reclaimed mixture are improved by the rotary compacting method, while the porosity and the optimal dosage of water are reduced. Furthermore, with the increase of compaction times, the porosity and splitting strength index both change exponentially. DWSSR and porosity are consistent with quadratic functions. The use of gyratory compaction for 70 times at 25 °C and the optimum dosage of emulsified asphalt can be determined based on the splitting strength ratio. The high-temperature stability and water damage resistance of the pavement can be improved by the use of rotary compacting method effectively, and the early strength and road performance are higher than the regulatory requirements.展开更多
The residue drying area(RDA)is the major source of fugitive red sand(RS)dust emissions in the bauxite mining industry and causes serious environmental and safety detriments.Polymer stabilizer(PS)is one of the promisin...The residue drying area(RDA)is the major source of fugitive red sand(RS)dust emissions in the bauxite mining industry and causes serious environmental and safety detriments.Polymer stabilizer(PS)is one of the promising non-traditional stabilizers to mitigate such issues.This research investigated the unconfined compressive strength(UCS)of RS using synthetic polymer stabilizer(SPS)and natural polymer stabilizer(NPS),and to determine the optimum application concentration and mixing ratio of the PAM and Guar gum mixture.Results illustrated that PAM apparently outperform Guar gum in stabilizing sand particles.The mixture of PAM and Guar gum is more effective than individual use.The optimum polymer concentration and the mixing ratio are 0.94 wt.%and 0.6(PAM:total(PAM+Guar gum)),respectively.A rigorous regression model was developed to predict the UCS value based on application concentration and mixing ratio for the purpose of cost and time efficiency.展开更多
Since the suspended sediments have severe influence on acoustic radiated field of transducer,it is significant for sonar system to analyze the influence of suspended sediments on acoustic pressure in the seafloor mini...Since the suspended sediments have severe influence on acoustic radiated field of transducer,it is significant for sonar system to analyze the influence of suspended sediments on acoustic pressure in the seafloor mining environment.Based on the KZK(Khokhlov-Zabolotkaya-Kuznetsov)equation,the method of sound field analysis in turbid water is proposed.Firstly,based on the analysis of absorption in clean water and viscous absorption of suspended sediments,the sound attenuation coefficient as a function of frequency in the mining environment is calculated.Then,based on the solution of KZK equation in frequency domain,the axial sound pressure of transducer in clear water as well as turbid water is simulated using MATLAB.Simulation results show that the influence of the suspended sediments on the pressure of near field is negligible.With the increase of distance,the axial sound pressures of transducer decay rapidly.Suspended sediments seriously affect the pressure in far-field.To verify the validity of this numerical method,experiment is designed and the axial sound pressure of transducer with a frequency of 200 kHz and a beam width of 7.5~is measured in simulated mining experiment.The results show that the simulation results agree well with the experiments,and the KZK equation can be used to calculate the sound field in turbid water.展开更多
Some effective parameters on the copper extraction from Kiire chalcopyrite concentrate were optimized by using response surface methodology （RSM）. Experiments designed by RSM were carried out in the presence of ammo...Some effective parameters on the copper extraction from Kiire chalcopyrite concentrate were optimized by using response surface methodology （RSM）. Experiments designed by RSM were carried out in the presence of ammonium persulfate （APS） and different types of impeller in an autoclave system. Ammonium persulfate concentration and leaching temperature were defined numerically and three types of impellers were defined categorically as independent variables using experimental design software. The optimum condition for copper extraction from the chalcopyrite concentrate is found to be ammonium persulfate concentration of 277.77 kg/m3, leaching temperature of 389.98 K and wheel type of impeller. The proposed model equation using RSM has shown good agreement with the experimental data, with correlation coefficients R2 and RaZaj for the model as 0.89 and 0.84, respectively.展开更多
基金Project (200550) supported by the Foundation for the Author of National Excellent Doctoral Dissertation of ChinaProject (09JJ1008) supported by Hunan Provincial Natural Science Foundation of China
文摘A new method was proposed to predict the limited compaction grouting pressure for the soft soils. Theoretical basis of the method considered the conical shear failure above the grout bulb. Using the Mohr-Coulomb yield criterion as the initial yield function, the limited compaction grouting pressure was determined, according to the softening elastic-plastic model based on the conventional triaxial compression tests to simulate the strain softening soils. The small strain in the elastic zone and large stain in the plastic zone and the rational yield function for the strain softening phase stage, the analytical solutions to the compaction grouting pressure were presented. The results indicate reasonable agreement and show a good potential of the proposed method for rationally optimizing the design of compaction grouting operations.
基金Projects(51708048,51704040)supported by the National Natural Science Foundation of ChinaProject(17C0050)supported by the Scientific Research Project of Hunan Provincial Department of Education for General Scholars,China+1 种基金Project(kfj160103)supported by the Open Fund of State Engineering Laboratory of Highway Maintenance Technology(Changsha University of Science&Technology),ChinaProject supported by the Open Fund of Guangxi Key Lab of Road Structure and Materials,China
文摘In order to study the application of gyratory compaction molding method in emulsified asphalt cold recycled mixture and optimize the relevant technical parameters, the study was carried out according to splitting strength, stability and water stability test;the design of the experiment involved changing gyration number, emulsified asphalt and water content, molded specimen temperature and other factors to analyze the volume parameters, mechanical properties and water stability. The results show that both the maximum dry density and dry and wet splitting strength ratio(DWSSR) of emulsified asphalt cold reclaimed mixture are improved by the rotary compacting method, while the porosity and the optimal dosage of water are reduced. Furthermore, with the increase of compaction times, the porosity and splitting strength index both change exponentially. DWSSR and porosity are consistent with quadratic functions. The use of gyratory compaction for 70 times at 25 °C and the optimum dosage of emulsified asphalt can be determined based on the splitting strength ratio. The high-temperature stability and water damage resistance of the pavement can be improved by the use of rotary compacting method effectively, and the early strength and road performance are higher than the regulatory requirements.
基金Project(2016YFC0501103)supported by the National Key Research and Development Program of ChinaProject(51574222)supported by the General Program of National Science Foundation of China+1 种基金Project(SKLCRSM15KF01)supported by Independent Research Projects of State Key Laboratory of Coal Resources and Safe Mining,CUMT,ChinaProject(2015)supported by the Mining Education Australia Collaborative Research Grant Scheme
文摘The residue drying area(RDA)is the major source of fugitive red sand(RS)dust emissions in the bauxite mining industry and causes serious environmental and safety detriments.Polymer stabilizer(PS)is one of the promising non-traditional stabilizers to mitigate such issues.This research investigated the unconfined compressive strength(UCS)of RS using synthetic polymer stabilizer(SPS)and natural polymer stabilizer(NPS),and to determine the optimum application concentration and mixing ratio of the PAM and Guar gum mixture.Results illustrated that PAM apparently outperform Guar gum in stabilizing sand particles.The mixture of PAM and Guar gum is more effective than individual use.The optimum polymer concentration and the mixing ratio are 0.94 wt.%and 0.6(PAM:total(PAM+Guar gum)),respectively.A rigorous regression model was developed to predict the UCS value based on application concentration and mixing ratio for the purpose of cost and time efficiency.
基金Project(51374245)supported by the National Natural Science Foundation of ChinaProject(10C0681)supported by Education Department of Hunan Province,China
文摘Since the suspended sediments have severe influence on acoustic radiated field of transducer,it is significant for sonar system to analyze the influence of suspended sediments on acoustic pressure in the seafloor mining environment.Based on the KZK(Khokhlov-Zabolotkaya-Kuznetsov)equation,the method of sound field analysis in turbid water is proposed.Firstly,based on the analysis of absorption in clean water and viscous absorption of suspended sediments,the sound attenuation coefficient as a function of frequency in the mining environment is calculated.Then,based on the solution of KZK equation in frequency domain,the axial sound pressure of transducer in clear water as well as turbid water is simulated using MATLAB.Simulation results show that the influence of the suspended sediments on the pressure of near field is negligible.With the increase of distance,the axial sound pressures of transducer decay rapidly.Suspended sediments seriously affect the pressure in far-field.To verify the validity of this numerical method,experiment is designed and the axial sound pressure of transducer with a frequency of 200 kHz and a beam width of 7.5~is measured in simulated mining experiment.The results show that the simulation results agree well with the experiments,and the KZK equation can be used to calculate the sound field in turbid water.
基金supported by the TUBITAK(Scientific and Technological Research Council of Turkey) under the Project No:106M177
文摘Some effective parameters on the copper extraction from Kiire chalcopyrite concentrate were optimized by using response surface methodology （RSM）. Experiments designed by RSM were carried out in the presence of ammonium persulfate （APS） and different types of impeller in an autoclave system. Ammonium persulfate concentration and leaching temperature were defined numerically and three types of impellers were defined categorically as independent variables using experimental design software. The optimum condition for copper extraction from the chalcopyrite concentrate is found to be ammonium persulfate concentration of 277.77 kg/m3, leaching temperature of 389.98 K and wheel type of impeller. The proposed model equation using RSM has shown good agreement with the experimental data, with correlation coefficients R2 and RaZaj for the model as 0.89 and 0.84, respectively.
