Applied Mechanics and Materials Vols. 423-426

Abstract: The anisotropy in the dam designs is a very important factor. In order to research the influence of anisotropy on seepage field of Dalong water control dam, this paper uses the three-dimensional finite element method to analyze the seepage characteristics and evaluate the safety of the dam by comparing the change characteristics of the pore pressure and velocity of the dam under the two different conditions.

Abstract: Based on the numerical simulation method, this paper has established the numerical simulation method by using of finite difference software of FLAC3D through establishing interface for digging pile-soil. It can consider mutual effect of digging pile-soil. The uplift bearing capacity of the digging pile in slope ground was calculated and the affecting factors of the bearing capacity were analyzed. The results show that the uplift bearing capacity has a negative correlation with the slope ratio, and has a positive correlation with the width or height of the foundation, which can be expressed as a quadratic polynomial. But when the slope ratio is smaller than a certain extent, the capacity no longer increases. Nonlinear regression analysis of calculation data are carried out. Finally, the calculation method of uplift bearing capacity about pile in the slope is developed, which can provide a reference to specification revision and engineering.

Abstract: The pile friction regular pattern in the slope has much difference with piles in the ground. By using the finite-difference software FLAC3D,the pile friction under the vertical load is studied. The regular pattern and influence factors are analyzed. The results show that there is a significant difference contrasting the friction of both sides of the pile. For the point of value, the friction closed to the slope-side is smaller than the friction away from the slope-side. The average is 60% to 70%. For the distribution, the friction closed to the slope-side decreases rapidly with the depth of the pile. The friction away from the slope-side distributes relatively evenly. The slope ratio and the pile location have a great impact on the friction. The friction has a negative correlation with the slope ratio, and has a positive correlation with the pile distance.

Abstract: Variation laws of cement stabilized iron tailings sand mixtures loss of water, dry shrinkage strain and temperature shrinkage coefficient have been obtained by the indoor shrinkage test, which are compared with cement stabilized gravel. Results of test show that its dry shrinkage strain are greater than cement stabilized gravel. There is no significant difference of temperature shrinkage coefficient between two mixtures above 273.15K, but this index of cement stabilized iron tailings sand mixture is significantly larger than that of cement stabilized gravel below 273.15K, which provides theoretical references for promotion and application of iron tailings sand in road engineering.

Abstract: As an important part of landslide risk assessment, hazard analysis which is based on the probability analysis of landslide stability have caught more and more attentions from researchers and engineers. While in landslide engineering, the uncertainties such as the variability and uncertainty inherent in the geotechnical properties are complex and different, so a single Factor of Safety calculated by traditional deterministic analyses methods can not represent the landslide stability exactly. To provide a more rational mathematical framework to incorporate different types of uncertainties in the landslide stability estimation, some practical probability analysis methods for stability of landslide were proposed, then the user-friendly implementing softwares were recommended. Finally, an application case was described to illustrate the approaches adopted and proved the correctness and feasibility of the proposed methods. The results show the proposed techniques can be applied widely.

Abstract: In order to reveal the damage characteristics of internal explosion, the internal explosion of closed RC structure under incremental charges manner until structural damage are simulated by LS-DYNA code. The weight changes of charge influence on structure damage and distribution law of characteristic parameter of shockwave on the typical position are also discussed in this paper. The results show that, the distribution of shockwave overpressure on the walls under different weight of charge obey three kinds of linear laws as following: affected by one wall, two walls and three walls, respectively. The distributions of impulse on the walls under different weight of charge obey their distribution curve respectively when the structure is undestroyed, but the impulse will deviate from the distribution curve when the structure is destroyed. And the damage situation of RC structure under internal explosion is graded。

Abstract: Soil Mechanics, as one of the most important basic courses in civil engineering, hydraulic engineering and other courses, mainly analyzes the questions of deformation and stability of the soli body. The undergraduates begin to learn soil mechanics after finishing advanced mathematics, college physics, theoretical mechanics and mechanics of materials. The objects researched in the above-mentioned courses are idealised, so the rigorous mathematic deduction is feasible and only a few hypotheses are needed. Soil is different from other materials, so inevitably the methodology and thinking mode in soil mechanics are special compared with other mechanical courses, which makes students feel confused at the beginning stage of this course. It is necessary to let students know the teaching idea, research method, common problems during the instruction of soil mechanics, which is also helpful to their further studies and researches. Based on these factors, an inductive teaching method is put forward, which summarizes the essential ideas and important questions in soil mechanics.

Abstract: Finite element method is used to compute the factor of safety of jointed rock slope. The stability of jointed rock slope is simulated by using shear strength reduction approach. Mohr-Coulomb fracture criterion is used to evaluate the sticking or sliding state of jointed rock mass. The distribution of plastic zone at collapse state is determined. Numerical computational results show that the proposed procedure is effective to evaluate stability of jointed rock slope.

Abstract: Submarine landslide can destroy various engineering facilities. So, submarine slope stability evaluation is not only an important link of the construction safety guarantee and soil mechanics in the new field of ocean direction, but also the development of energy demand. Based on the finite element software Abaqus, the strength reduction method has been introduced to submarine slope stability evaluation. With the same finite element model, the safety factors of the land slope and submarine slope are respectively 1.82, 1.83, and 1.205, 1.215, using two criterions such as run-through of plastic zone and run-through of the equivalent plastic strain zone. The studies show that the submarine slide has the following characteristics: the displacement is 5~10 times larger than that of landslide; the obvious " uplift " and " collapse " phenomenon appears near the slope toe and the top of slope; the slide region is much more wider, deeper, less clearly slip shear zone boundary.

Abstract: According to the seepage action of hard rock fissure water, a numerical simulation method is proposed in this paper. The basic mechanical properties for rock mass changed significantly during the process of secondary stress adjustments, and the rock deterioration constitutive model (RDM) can accurately reflect both the abruptness of the rock yield failure and the changes of mechanical parameters after yield. On the basis of RDM, the permeability coefficient with equivalent plastic strain function was introduced in this method which can update the permeability coefficient, and carried out numerical simulation on hard rock fissure water seepage action by FLAC^3D. The results of the seepage triaxial compression experiment proved the rationality of the method.