Applied Mechanics and Materials Vols. 501-504

Abstract: The cyclic fluctuation of reservoir water level makes soft rock in bank slope under cyclic seepage pressure and will bring certain effects on permeability characteristics of the soft rock. In order to obtain the relationship between the seepage pressure and seepage time, permeability tests were conducted on red sandstone specimens (from Three Gorges Reservoir Area, China) under cyclic seepage pressures by the self-developed equipment with the function to simulate cyclic fluctuation of reservoir water level. Experimental results show that the water infiltration of the sample was not stable in first three cycles, and it changed from 0.444 mL to 0.086mL. After three cycles, the water infiltration fluctuated between 0.060mL and 0.069mL. It can be drawn that the seepage velocity increase with the raise of pressure and it fit a four times polynomial in each cycle. The study indicates that increasing the seepage pressure appropriately can improve the seepage velocity, and greatly shorten the seepage time.

Abstract: This paper summarizes and analyzes the basic concepts and ecological protection mechanism for expansion geotechnical slope failure mechanism and the resulting impact on the shallow, traction engineering properties such as analysis, proposed ecological slope of expansive soil slope mechanism of action: vegetation system by improving internal slope soil moisture and temperature changes affect the atmosphere and thus effectively reduce the depth. Vegetation root through reinforced anchoring, delay time and improving soil hydration ductility such as the role played good strength enhancement. Vegetation formation can effectively improve the damaged outer slope interface morphology, to restore the ecological environment and landscape effect. Integrating the past experience on expansive soil slope treatment, this paper provide a slope treatment method used in Nanning metro Tunli section, these will provide reference for the expansive soil slope ecological management.

Abstract: Soil erosion continues to be one of the world's biggest environmental problems. Understanding processes of rill and interrill erosion is the key to develop soil erosion prediction models that can provide a scientific basis for soil and water conservation planning. This thesis introduced REE tracing method briefly, and reviewed the application of REE trace method in s rill and interrill erosion soil erosion from slope respectively. Finally, the shortcomings in current studies and the important direction of future researches were pointed out that could provide scientific references for improving the REE tracing method and extending its application in wider research areas.

Abstract: By using the finite element method we had studied the Tianjin Expressway Subgrade Settlement.Through the comparison of the reinforcement and the unreinforced two case we studied the principles of strengthening soft soil subgrade and results show that the mixing pile to improve the bearing capacity of the embankment foundation, reduce the settlement of foundation has played a very good role.The finite element method can reflect the nonlinear characteristics of the coupling effect between composite foundation pile, soil and the soil around the pile, the soil using elastoplastic model, and considering the different medium, different distribution,which has great advantages in the analysis of various factors.The finite element method can better reflect the reinforcement of soft soil subgrade.So ,it also can optimize the engineering design.

Abstract: This article uses the extenics and fuzzy hierarchy analysis method,on the slope stability analysis method of uncertainty is improved.At the same time,on the measured data report AnTaiBao open-pit mine for practical engineering,using the method of the north, a risk evaluation is made on the stability of slope area.Through the engineering example of calculation shows that,in this paper, the risk evaluation method is reliable and can be used to guide the slope mining design.

Abstract: The strength parameters of jointed rockmass is estimated by Hoek-Brown criterion based on Geological Strength Index (GSI).The estimation process is demonstrated by an example , the study shows that it is an economic, practical, and efficient method to estimate the rockmass strength parameters .

Abstract: Rockburst is modeled in this paper by the theory of elastoplastic damage at finite stains. Isotropic damage coupled with elastoplasticity is assumed and multiplicative kinematics in a purely mechanical setting is further applied. Merging the finite strain plasticity framework of Simo and the thermodynamics with internal variables of Lemaitre in definition of damage including processes, the Helmholtz free energy is additively decomposed to characterize the basic mechanism of elasto-plasticity and damage of brittle materials. The numerical simulations for granite burst are conducted by finite element technique.

Abstract: An adaptive neuro-fuzzy inference system (ANFIS) model has been developed to predict frost heaving in seasonal frozen regions. The structure of ANFIS is initialized by the subtractive clustering algorithm. The hybrid learning algorithm consisting of back-propagation and least-squares estimation is used to adjust parameters of ANFIS and automatically produce fuzzy rules. The data of frost heaving test obtained from a literature are used to train and check the system. The predicted results show that the proposed model outperforms the back propagation neural network (BPNN) in terms of computational speed, forecast errors, and efficiency. The ANFIS based model proves to be an effective approach to achieve both high accuracy and less computational complexity for predicting frost heaving.

Abstract: The infiltration process of infinite slopes was studied with modified Green-Ampt infiltration model. The process was divided into two stages, in which the depth of the wetting zone and underground water was calculated. Stability analysis considering different sliding patterns was conducted on the basis of seepage analysis. The safety factor of infinite slopes at different time stages has been derived. Equations in this paper could be used for predicting rain-induced landslides with limited parameters available.

Abstract: Stability analysis of steep rock bedding slope with weak structure planes using strength reduction method was simulated in this paper. The post processing function can display the development condition of the plastic zone, which is the criterion for instability of the slope. Analysis with working conditions of natural circumstance, after excavation, and the slope reinforced by anchor shank after excavation were put forward. Failure modes and safety coefficients of the slope proved that weak plane is the main factor controlling slope failure. Simulation results shown that strength reduction method is appropriate in predict the shape and position of the potential failure surface of steep rock bedding slope.