Applied Mechanics and Materials Vols. 170-173

Abstract: The discoveries of oil in YM32, the fluid oil and abundant secondary porosity in TS1 well provide the exploration of deep dolostone in Tarim basin with important references. The dolomites are characterized by old age, deep burial and complex diagenesis, thickly and extensively distributed in Cambrian stratum. The spaces of the Cambrian dolomite reservoir are composed of three groups: pores, fractures and combinations. And the dissolved pore and hole, the dissolved fracture and the combinations are absolutely in advantage. The paper discussed the main factors controlling the development of the dolomite reservoirs, and proved that the favorable sedimentary facies belts, various corrosions and hydrothermal activities are the key factors to form favorable dolomite reservoirs. Especially, the favorable sedimentary facies belts are the base of good dolomite reservoirs, the syngenetic karst and dolomitisation laid a solid foundation for secondary pore, and the hydrothermal corrosion is the key factor for well developed dolomite reservoirs.

Abstract: In recent year, the foundations of the stability analysis of slope were provided by the development of finite element and discrete element method. Using finite element and discrete element method, the stability analysis of three typical slopes of shiwu thorp of Quzhou was carried out. The safety factors of slope profile were obtained. Based on the judgment criterion of slope stability，the slopes stability of shiwu thorp was judged. The results showed that the way to analyze the stability of soil slope is feasible.

Abstract: In order to select an appropriate foundation treatment of peat soil, a theoretical analysis of peat soil foundation under well ditch treatment was conducted. By contrasting the settlements of well ditches and that of no treatment, the results show that well ditch treatment have advantages in acceleration of the consolidation of peat soil foundation. So well ditch treatment is suitable for peat soil foundation.

Abstract: Abstract. A secondary development of the ADINA software for Duncan-Chang E-B nonlinear elastic constitutive model was conducted in this paper, and the veracity of calculation results was verified. To contrast linear constitutive model and Duncan-Chang nonlinear constitutive model, the deformation of YuXi basin profile model under gravity action was calculated by both of the constitutive models. The results show that the subsidence in the linear results is about 12% larger than the nonlinear results, and the nonlinear model has advantages in parameter choosing. Meanwhile, a modified model of YuXi basin which depends on the latest data from our recent work in YuXi area was built to compare with the original model, the calculation results show that the changes in the basin basement structure and basin depth have great influence on the distribution and maximums of the deformation results, when the changes in the internal structure and sequence influence relatively little.

Abstract: There are general three kinds of means to research the mechanical properties of soil-structure interface, and they are soil-structure contact experimental studies, constitutive model and numerical calculation. Through the tests, the observation and measurement results in different experimental conditions can be obtained about soil-structure interface stress-strain characteristics, and then basing on the existing constitutive model theory researchers can put forward reasonable explanation to the phenomenon of the tests. Finally the constitutive model theory can be applied to the numerical calculation to predict and reproduce the test phenomenon, so as to fully reveal the nature of the soil-structure interface mechanical characteristics.

Abstract: Shanxi downed-faulted basin mainly consists of Datong basin, Taiyuan basin, Linfen basin and Yuncheng basin, having thick quaternary stratum. Affected by geological structure, topography, stratum conditions and other factors, ground fissure disasters are well developed. Using the development and evolution of tectonic-type ground fissures in the faulted basin as research objects, from the two aspects of horst-graben structure and basal activity of fault belt, this study explored the causes of quaternary ground fissures in Shanxi down-faulted basin. Studying the distribution characteristics, formation mechanism and the disaster-causing effects has the theoretical significance of a better summary and understanding on ground fissures and other geological disasters, as well as providing theoretical basis for prediction and prevention means of the disasters.

Abstract: Abstract. During the normal operation of Three Gorges Reservoir, the water level of the reservoir will fluctuate periodically, which will soften and decrease the shear strength of rock soil on the bank, meanwhile decrease the landslide stability. Huangtupo landslide is a typical large and complex landslide in the Three Gorges Reservoir Region, which is consist of four sub-landslides. In particular, the stability of its riverside Huangtupo I# landslide has a great stake. Based on the analysis of engineering geological condition of Huangtupo landslide, the 2D finite element model of Huangtupo I# landslide(The Riverside Slumping mass I#) was established, the proper mechanical parameters was selected. By using the GeoStudio software, according to the reservoir running curve, the simulation on coupling effect of seepage field and stress field was conducted in 7 different modes within the period of one year. The results showed that: ①the reservoir water level fluctuations will affect both the displacement in saturated and un-saturated area of landslide; especially when the water level drawing down sharply; ②the stability coefficient of Huangtupo I# changes with the reservoir water level fluctuations; the minimum stability coefficient occurs 48 days after the water level drawing down and the moment when the water level falls by 11.9m, under that moment the Huangtupo I# is unstable.

Abstract: A large-scale accumulation body, lying in left bank of a hydropower station dam, its stability is directly related to dam construction and operation. By means of engineering geological investigation on geological characteristics and geneses of accumulation body, the result shows the accumulation body is generally stable. Then, safety factor of accumulation body under different working conditions are calculated separately according to the method of EMU, The result shows that side slope is wholly stable and it can meet the stability requirements while the stability of section Ⅲ needs more studies. 3D model is built and applying FLAC program on stability of accumulation body under diverse conditions, it also shows that the whole stability of accumulation body is in a comparatively good condition. However, the possibility of partial slide still exists, and for this reason corresponding protections and reinforcements are proposed at last.

Abstract: Rock mechanics parameters are important during engineering investigation, design and construction, especially elastic modulus and Poisson’s ratio. According to the end point of initial fracture compression stage and elastic proportional point of stress-strain curve, the elastic deformation stage was determined; then the modulus and Poisson's ratio of rock at different strain rates were calculated by use of the average method. The results indicate that elastic modulus of rock increases with increasing strain rates; Poisson's ratios are scattered, but also present increasing trend.

Abstract: To prevent water bursting in mining coals and boring tunnels, analysis of water abundance of aquifer has to be done firstly. Based on analysis of main factors that can influence the water abundance of aquifer, five indices were used-aquifer thickness, drilling fluid consumption, structure distribution density, specific capacity and permeability coefficient. And the fuzzy analytic hierarchy process was introduced to determine the weight of each factor. Combining the data management and spatial analysis of GIS, we calculated and estimated the characteristic of water abundance for the study area. Due to the wide variance of water abundance over the whole study area, we set five rates to show the different results. So the study area was divided into five parts whose water capacity from high to low. The division was consistent with the hydro-geological conditions. So our method could be an alternative.