Applied Mechanics and Materials Vols. 353-356

Abstract: The wire-line coring hydraulic hammer drilling technique was used in the drilling process of gold mine of Henan province, which has solved the problems in a deviated formation. Based on the introduction of field situation, drilling equipments, drilling tool selection and performance parameters of wire-line coring hydraulic hammer, the main factors of hole deviation and prevented measures were discussed and also the deviation mitigation effect of this technology were analyzed and evaluated.

Abstract: The black shale enriched in various precious metal elements and platinum group elements. And the PGE deposit in black shale series is a new promising mineral resource. Comprehensive research on the geology, geochemistry, petrology, mineralogy, fluid inclusion and geochronology of the PGE in black shale series has been carried out and made a series of achievements. This paper summarized the advances in PGE in black shale series and pointed out the controversial views about the source of the PGE.

Abstract: The Mesozoic Hukeng granite body locates in southeast limb of Wugongshan compound anticline in Jiangxi Province, South China. This study uses samples from the Hukeng granite body to determine the characteristics of Sr-Nd-Pb isotopes and source of the granite body. The rocks have ⁸⁷Sr/⁸⁶Sr ratios as high as 0.84112, suggesting that crustal contamination existed there. The rocks have higher ratios of ⁸⁷Rb/⁸⁶Sr, ⁸⁷Sr/⁸⁶Sr and (⁸⁷Sr/⁸⁶Sr)_i, and lower ratios of ¹⁴⁷Sm/¹⁴⁴Nd, ⁴³Nd/¹⁴⁴Nd and lower ε_Nd(t), indicating that the Hukeng granite body possessesEMⅡ-like characteristics. Combined with Pb isotopic values (²⁰⁶Pb/²⁰⁴Pb ratios from 18.5313 to 18.8460, ²⁰⁷Pb/²⁰⁴Pb ratios from 15.6562 to 15.6782 and ²⁰⁸Pb/²⁰⁴Pb ratios from 38.7015 to 38.7565), the Hukeng granite body originated from EMⅡ and suffered crustal contamination in certain extent.

Abstract: The pore structure of coal rock atYangquan Xinjing mine in Shanxi Province is analyzed with mercury intrusion porosimetry to obtain the specific pore volume data and calculate the fractal dimension of coal pore surface. The pores are divided into macropore, mesopore and micropore according to radius size considering the calculated fractal dimension. The distribution characteristics of pore radius size, specific surface area and specific pore volume of different types are effectively analyzed. The research results show that mesopore surface has significantly fractal characteristics, which features could be discussed quantitatively. The proposed method in this paper has reference significance for studying the sorption and desorption properties, the diffussion and permeation of coalbed methane.

Abstract: Surface wave dispersion imaging approach is crucial for multi-channel analysis of surface wave (MASW). Because the resolution of inversed S-wave velocity and thickness of a layer are directly subjected to the resolution of imaged dispersion curve. The τ-p transform approach is an efficient and commonly used approach for Rayleigh wave dispersion curve imaging. However, the conventional τ-p transform approach was severely affected by waves amplitude. So, the energy peaks of f-v spectrum were mainly gathered in a narrow frequency range. In order to remedy this shortage, an improved τ-p transform approach was proposed by this paper. Comparison has been made between phase shift and improved τ-p transform approaches using both synthetic and in situ tested data. Result shows that the dispersion image transformed from proposed approach is superior to that either from conventionally τ-p transform or from phase shift approaches.

Abstract: The pore characteristics of saturated clay sourced from microstructure pictures in Pearl River Delta region of south China is analyzed considering the microstructure in different sample sections. The histogram statistics are compared with each other by pore data in terms of the size, the shape and the arrangement of link status. The repercussions of including the anisotropy ratio law of pore characteristics are focused to study saturated clay. It is found that the analysis considering anisotropy ratio results in consolidation by pore distribution based on saturated clay microstructure. The soil porosity of horizontal section was larger than that of vertical section. Vertical section status induced the directional property, and it would be presented directional probability entropy which is able to calculating the chaos of overall arrangement which is a lower value because of directional property.

Abstract: Prediction problem of large catastrophic landslide is an important applied research topic of geotechnical mechanics. This paper made the detailed geology survey and analysis for the Xiapuzi landslide; based on the analysis of the rainfall data, analyzed landslide body stability under rainfall influence. Using deformation monitoring data,relationships were analyzed between rainfall infiltration time, critical rainfall and total rainfall,with the deformation of landslide, and the relationship between deformations incremental with the rainfall. Results provided a basis for choice of landslide treatment measures. The research accumulated experience for treatment of similar landslide geological disasters.

Abstract: This paper focused on calculation of gushing water and evaluation of calculation methods. A groundwater runoff modulus method, a rainfall infiltration coefficient method and a groundwater dynamics method were used to calculate volume rate of water inflow of an ultra deep buried long tunnel under conditions of high water pressure and high ground stress (referred to as two high conditions). Results show that the more volume rate of water inflow occurs in a fault zone with fault gouge, a karst stratum zone and their combination zone. The calculation results by using modified Goodman formula have the highest precision. The results can provide prevention of gushing water of a deep buried long tunnel under the two high conditions with scientific basis.

Abstract: In this paper, using geophysical exploration methods, it investigates the distribution characteristics of the S243 Yuxian road sections' mined areas, ground fissures, collapse columns and underground of the soil cave, analyzes the main causes of collapse, and makes a rational management program.

Abstract: Large amount of loose deposits and potential geo-hazards were formed by Wenchuan earthquake, which would be transformed into collapses, landslide and debris flows under the condition of rainfall or aftershock. The paper divides influence factors into triggering factors and background factors, and constitutes susceptibility forecast system for geo-hazard based on factors in parallel or series. The background system contains stratum, distance to river, relief, slope and aspect of slope. And the triggering system includes distance to seismic fault and rainfall. The paper applies and verifies the system to forecast the susceptibility of geo-hazard in study area, and the result shows that 52 small watersheds are in extremely high and high states accounting for 37.68% in 138 small watersheds. According to the statistics of 23 geo-hazards from field investigation, 13 geo-hazards are in extremely high risk grade of susceptibility and 10 geo-hazards are in high risk grade of susceptibility, which shows that the result of susceptibility forecast of geo-hazard is reasonable.