Applied Mechanics and Materials Vols. 204-208

Abstract: Aiming at researching on stability of high filling slope effected by precipitation duration. Transient saturated-unsaturated seepage method and slope stability finite element method is combined in this paper. Vadose field of slope is simulated in different precipitation duration condition. On the basis of vadose field author analyses the stability of slope effected by precipitation duration. The research results indicate that change of the pore water pressure is mainly concentrated in the position where the water level changes in the process of precipitation. After the precipitation pore water pressure gradually dissipates. Precipitation duration has great effect on the slope stability. With the precipitation duration increases the slope safety coefficient decreases. The slope safety coefficient decreases in the process of precipitation, but after precipitation, it increases gradually and eventually be more stable. The longer the precipitation duration is, the longer time that the safety coefficient reaches the ultimate stability required.

Abstract: Wind erosion may appear because of the construction of embankment in a non-wind-eroded area. It can cause the destruction of the embankment and bring about flying dust, to which little attention has been paid. Based on analysis of the embankment-caused acceleration of wind, a design method under consideration of wind erosion is put forward for embankment in the non-wind-eroded area. Then protection range for the embankment is suggested and countermeasures against wind erosion are given. The results of this paper help render the design of embankment more reasonable and environmentally friendly.

Abstract: Grey linear regression model is a covert grey combined model that is built based on GM(1,1) model and linear regression model. It improves undervaluation of linear regression model which can not in press the exponential growth and come to deficiency of grey GM (1, 1) model which has not linear factor. This paper briefly introduces the establishment and precision examination method of the grey linearity regression model and establishes the grey linear regression model to predict the relationship of load and settlement. Based on the data of static load test, the load-settlement curve is simulated and analyzed. The result of study shows that Grey Linear regression Model can effectively predict the settlement of pile foundation, and be of the theoretical and actual meaning for further analyzing the bearing capability of pile foundation.

Abstract: Bio-mediated soil improvement is a relatively young technology in geotechnical engineering. The practical applications of the technique are still exposed to some uncertainties. This paper investigated the effect of the concentration of the cementation reagent on the performance of bio-mediated soil improvement. The shear strength, calcite content, pH, and ammonium content of the bio-mediated soil were measured under three concentrations of a cementation reagent, i.e. 0.25 M, 0.5 M, and 1 M. The results showed that the calcite precipitation and shear strength improved with the increased concentration of the cementation reagent up to 0.5 M. However, the improvement was retarded at higher concentration (i.e. 1.0 M). This is likely due to the inhibitory effect and halophilic characteristic of the bacteria used for the biocementation

Abstract: This article describes the Xingtai City, a typical large-scale modern coal mine, mine environmental geological problems arising due to the exploitation of coal resources, and the corresponding countermeasures and suggestions for different problems. Mainly introductions are the destruction of water resources, mine water hazard, mining subsidence and destruction of land resources, and guiding role in the safe production of coal and the surrounding environmental governance.

Abstract: Freeze-thaw made the microstructure of the soil produce a certain degree of damage, which was relevant with the soil water content. 6 kinds of remolded soil of the water content was prepared, at low temperature of freezed, in room temperature of melt, after not consolidated non-drained triaxial compression test, the soil shear strength parameters was determined. The results show: after thawed, soil shear strength had reduced significantly, and water content exerted such a pronounced effect on strength of reducing amplitude. Accordingly, the relationship of shear strength reducing after thawing of remolded soil and the water content was set up preliminarily.

Abstract: Accurately predicting the subgrade deep horizontal displacement is important to subgrade stability. The study on subgrade deep horizontal displacement is not sufficient. It studies several displacement prediction methods,and builds matching prediction models to predict horizontal displacement. Referring to the posteriori error ratio and small error probability, we get the following results. GM(1,1) model is suitable for predicting the subgrade horizontal displacement,and the trend of GM(1,1) model is consistent with actual values. Its accuracy is higher than the logarithmic curve fitting.What more, the stability is better than the exponential smoothing model.

Abstract: According to the project, this paper discusses the constitution and site construction plan of the slope flexible protection system, and analyzes its design mechanism. Under different geological conditions and different environment, it compares slop flexible protection system with other slope treatment methods in design, construction, and economic effect. This paper concludes when it can achieve the best practicality, applicability, and economic effect.

Abstract: The paper proposed a simulating arbitrary slip surface method. For simulating slip surface, select 7 control points, then connect to broken line which is assumed slip surface. Horizontal spacing between 7 control points is not equal, the spacing is arbitrary. Horizontal spacing of general simulating slip surface method is equal. So the proposed method is closer to the actual. For search method, particle swarm algorithm is not easy to fall into local minima, as a global intelligent optimization method, particle swarm algorithm is suitable for search the most dangerous slip surface. Based Janbu method, the paper computed two examples for simple slope and complex slope. The results show that the proposed method is effective.

Abstract: The incipient motion mechanism of cohesive fine sediment is different to the one of non-cohesive sediment. It is related to the consolidation while being influenced by the dry unit weight and particle size. By means of the rectangle piping flume, the influence mechanism of dry unit weight and particle size to critical shear stress of cohesive fine sediment is studied. Experimental results show that on the condition of consolidation, the influence of dry unit weight to incipient motion is divided into two different stages, one is that when dry unit weight increase quickly, but the influence to incipient motion is not greatly, another is that when dry unit weight increase slowly, but the influence to incipient motion is very greatly, the critical dry unit weight to two stages decline as mean particle size decrease. So the mean particle size is finer, the degree of dry unit weight influence to critical shear stress is stronger, and the incipient motion is more difficult when consolidation last longer; it is also shown consolidation is more disadvantageous to incipient motion.