An unsaturated clay slope, with various sloping angles and a thickness of 14 m, consists of backfill, slope soil and residual soil. Slide interfaces were determined by geophysical approaches and the original slope was reconstructed. Sub-slope masses were classified based on the varieties of sloping angle. A force recursive principle was proposed to calculate the stability coefficient of the sub-slope masses. The influencing factors such as sloping angle, water content, hydrostatic pressure, seismic force as well as train load were analyzed. The range and correlation of the above-mentioned factors were discussed and coupled wave equations were established to reflect the relationships between unit weight, cohesion, internal frictional angle, and water content, as well as between internal frictional angle and cohesion. The sensitivity analysis of slope stability was carried out and susceptive factors were determined when the factors were taken as independent and dependent variables respectively. The results show that sloping angle, water content and earthquake are the principal susceptive factors influencing slope stability. The impact of hydrostatic pressure on slope stability is similar to the seismic force in quantity. Train load plays a small role in slope stability and its influencing only reaches the roadbed and its neighboring slope segment. If the factors are taken as independent variables, the influencing extent of water content and cohesion on slope stability can be weakened and train load can be magnified.
针对香港风化花岗岩场址勘探,在液压旋转钻机上安装钻孔过程监测系统(drilling process monitoring,DPM),对有效轴压力、钻具转速、冲洗压力、钻头位移及穿孔速率进行了实时监测.采用变斜率作为显著性指数,对地层中的主、次界面进行了识别.t检验表明,DPM系统对岩土界面识别的置信度为99%.此外,对穿孔参数在界面处的变化分析表明,这些参数随孔深的变化曲线在界面处存在不同涨落,轴压力和穿孔速率对界面上岩石强度变化的响应度为81.82%.
A quantitative analysis of the porosity,pore size distribution,and fractal dimensions of pores is significant for studying the pore structure characteristics of coal.This study utilized 12 anthracite coal samples from the Sihe mining area to explore the pore structure characteristics of the coal therein.Hundred randomly selected points on each sliced coal sample were imaged via scanning electron microscopy,and a total of 1200 images were used for the analysis.The porosity and fractal dimensions of the coal samples were analyzed via digital image processing and box-counting dimension methods.This method is characterized by extensive graphical analysis,and the results are based on statistical methods.These were also used to analyze the structural and development characteristics of the microscopic pores in the coal.The results reveal that the surface porosity obtained via digital image processing was 16.11%lower than that measured experimentally.The fractal dimension and porosity of the pore surface were fitted to a natural logarithmic curve.The rate of change in the pore fractal dimension depends on the porosity such that,to some degree,a greater porosity is associated with more complex pore structures,a higher degree of micropore development,and improved pore connectivity.
Guangui ZouJiasheng SheSuping PengQuanchun YinHongbin LiuYuyan Che
