Non-consistency of stress results is of ten observed during field measurements. In some cases, even the rneasurernents are made at the same location in a massive rockrnass, the results can vary widely. In order to sol...Non-consistency of stress results is of ten observed during field measurements. In some cases, even the rneasurernents are made at the same location in a massive rockrnass, the results can vary widely. In order to solve the problem, extensive research has been carried out to study the major factors wh1ch rnay affect stress deterrnlnation. They include the rock behaviour and the stress state. For rocks showing non-isotropic behaviour, the values of Young’s modulus and Poisson ratio vary with the orientation of loading and measurement. Stress condition in the rock affects the rock behaviour. Furtherrnore, the loading condition on rock samples durlng laboratory tests is different from in the field and therefore the determined e1astic constants may not represent the field condi tion. In general , the Young’s modulus may depend on the orientation, the loading path, the stress magnitude and the stress ratio. This paper examines in detail the effects of those factors, especially for rocks showing transversely isotropic behaviour. It is found that the discrepancy of stress results from field measurernents in this type of rock is mainly due to over simplification of the rock behavior and inadequate use of elastic constants of the rock during stress calculation. A case study is given,which indicates the significance of these factors and demonstrates the proper procedure for stress calculation from measurements.展开更多
The main objective of this study was to determine the consolidation behaviour of clay slurries.A finegrained clay with high consistency limits(W_L = 180%,w_P= 120%) was investigated using conventional oedometer and be...The main objective of this study was to determine the consolidation behaviour of clay slurries.A finegrained clay with high consistency limits(W_L = 180%,w_P= 120%) was investigated using conventional oedometer and bench-top centrifuge tests.Results indicated that the slurry had an apparent preconsolidation(due to initial conditions,electrochemical interactions,tortuous drainage,and thixotropic strength) from e = 5.7 to e = 5.5 followed by virgin compression.Likewise,the low hydraulic conductivity(10^(-10)-10^(-12) m/s) was due to low porosity(small pore throats) and high tortuosity(long flow paths).Unlike consolidation of soils,the c_v and m_v decreased with increasing σ' but increased with increasing e and k.The data from the two tests correlated well in the range of σ' = 10-65 kPa,e = 5.5-3.86,k= 1.7 × 10^(-10)-5×10^(-11) m/s,F_c = 1-40 MN.New equations were developed to correlate the consolidation parameters(e,σ',k) with F_c.The deviation of k beyond 40 MN(e = 4.65) was due to deviation from the initial straight line portion of the settlement curve in the centrifuge test.展开更多
In this paper, the first generation and second generation of Chilo suppressalis Walker were conducted as the test objects to investigate control of a new pesticide(chlorantraniliprole) with preparation of chlorantrani...In this paper, the first generation and second generation of Chilo suppressalis Walker were conducted as the test objects to investigate control of a new pesticide(chlorantraniliprole) with preparation of chlorantraniliprole 20% SC,abamectin 1.8% EC and chlorpyrifos 40% EC to Chilo suppressalis Walker. The results showed that chlorantraniliprole 20% SC, abamectin 1.8% EC and chlorpyrifos40% EC had effective control to Chilo suppressalis Walker for its excellent control efficacy and long persistence period. Seedling protection efficacies were between84.2%-100%, 90.1% and 92.1%, and insecticidal efficacies were between 84.6%-100%,90.7% and 93.8% 36 days after application of chlorantraniliprole 20% SC in treatments with abamectin 1.8% EC and chlorpyrifos 40% EC for first generation Chilo suppressalis Walker control. The dead panicles were between 0.2%-1.4%, 0.8%and 0.7%, pest plant rate control in 0.4%-2.2%, 1.1% and 0.9%, and the rates of damaged rice plants were between 82.4%-97.6%, 90.2%-91.2% and 91.4%-92.8%,30 days after application of chlorantraniliprole 20% SC, abamectin 1.8% EC and chlorpyrifos 40% EC for the second generation Chilo suppressalis Walker control. It can effectively protect seedlings, protect spike, increase grain number and grain weight, which promoting the increase production income effect. The real estate increased by 9.7%-12.3%, 10.9% and 11.2% than water treatment(CK) with a very significant level, while the incomes were higher than 1 719.19-1 998.22, 1 956.52 and 2 057.83 yuan.展开更多
文摘Non-consistency of stress results is of ten observed during field measurements. In some cases, even the rneasurernents are made at the same location in a massive rockrnass, the results can vary widely. In order to solve the problem, extensive research has been carried out to study the major factors wh1ch rnay affect stress deterrnlnation. They include the rock behaviour and the stress state. For rocks showing non-isotropic behaviour, the values of Young’s modulus and Poisson ratio vary with the orientation of loading and measurement. Stress condition in the rock affects the rock behaviour. Furtherrnore, the loading condition on rock samples durlng laboratory tests is different from in the field and therefore the determined e1astic constants may not represent the field condi tion. In general , the Young’s modulus may depend on the orientation, the loading path, the stress magnitude and the stress ratio. This paper examines in detail the effects of those factors, especially for rocks showing transversely isotropic behaviour. It is found that the discrepancy of stress results from field measurernents in this type of rock is mainly due to over simplification of the rock behavior and inadequate use of elastic constants of the rock during stress calculation. A case study is given,which indicates the significance of these factors and demonstrates the proper procedure for stress calculation from measurements.
基金the University of Regina for providing laboratory space and the Natural Science and Engineering Research Council of Canada for financial assistance
文摘The main objective of this study was to determine the consolidation behaviour of clay slurries.A finegrained clay with high consistency limits(W_L = 180%,w_P= 120%) was investigated using conventional oedometer and bench-top centrifuge tests.Results indicated that the slurry had an apparent preconsolidation(due to initial conditions,electrochemical interactions,tortuous drainage,and thixotropic strength) from e = 5.7 to e = 5.5 followed by virgin compression.Likewise,the low hydraulic conductivity(10^(-10)-10^(-12) m/s) was due to low porosity(small pore throats) and high tortuosity(long flow paths).Unlike consolidation of soils,the c_v and m_v decreased with increasing σ' but increased with increasing e and k.The data from the two tests correlated well in the range of σ' = 10-65 kPa,e = 5.5-3.86,k= 1.7 × 10^(-10)-5×10^(-11) m/s,F_c = 1-40 MN.New equations were developed to correlate the consolidation parameters(e,σ',k) with F_c.The deviation of k beyond 40 MN(e = 4.65) was due to deviation from the initial straight line portion of the settlement curve in the centrifuge test.
基金Supported by Notice on the First Batch of National Modern Agricultural Demonstration Zone by the Ministry of Agriculture(Agricultural Project No.[2010]22)
文摘In this paper, the first generation and second generation of Chilo suppressalis Walker were conducted as the test objects to investigate control of a new pesticide(chlorantraniliprole) with preparation of chlorantraniliprole 20% SC,abamectin 1.8% EC and chlorpyrifos 40% EC to Chilo suppressalis Walker. The results showed that chlorantraniliprole 20% SC, abamectin 1.8% EC and chlorpyrifos40% EC had effective control to Chilo suppressalis Walker for its excellent control efficacy and long persistence period. Seedling protection efficacies were between84.2%-100%, 90.1% and 92.1%, and insecticidal efficacies were between 84.6%-100%,90.7% and 93.8% 36 days after application of chlorantraniliprole 20% SC in treatments with abamectin 1.8% EC and chlorpyrifos 40% EC for first generation Chilo suppressalis Walker control. The dead panicles were between 0.2%-1.4%, 0.8%and 0.7%, pest plant rate control in 0.4%-2.2%, 1.1% and 0.9%, and the rates of damaged rice plants were between 82.4%-97.6%, 90.2%-91.2% and 91.4%-92.8%,30 days after application of chlorantraniliprole 20% SC, abamectin 1.8% EC and chlorpyrifos 40% EC for the second generation Chilo suppressalis Walker control. It can effectively protect seedlings, protect spike, increase grain number and grain weight, which promoting the increase production income effect. The real estate increased by 9.7%-12.3%, 10.9% and 11.2% than water treatment(CK) with a very significant level, while the incomes were higher than 1 719.19-1 998.22, 1 956.52 and 2 057.83 yuan.
