Applied Mechanics and Materials Vols. 170-173

Abstract: A pile-soil interface model was established. The model considered the influence of interface lateral stress on the interface mechanics parameters. In this model the ultimate shear stress and the max tangential stiffness in loading process were related with pile lateral stress ratio. The influence of loading model on pile side resistance can be considered in this model. With the model, the interface parameters under pressing down at pile top can be got from those under pushing at pile bottom load. The suggested model was applied to analyze an O-cell pile test case. The analysis results show that the bearing capacity under loading press at pile top is higher than that under pushing at pile bottom, and the increase extent is agree with practical experience. It is also confirmed that the model is applicable and effective.

Abstract: The dynamic shear modulus (DSM) is the most basic soil parameter in earthquake or other dynamic loading conditions and can be obtained through testing in the laboratory and in the field. The experimental result of maximum DSM by using resonant column devices is compared with the field test data obtained from shear wave velocity measurement in the paper. By testing two engineering sites, the reason of difference of the maximum DSM between laboratory and field test is presented and the effect of the consolidation ratio on the maximum DSM is investigated. The results here indicate that consolidation ratio is one of the most important influence factors to make a great difference of the maximum DSM between laboratory and field test. By comparing to the isotropic consolidation, the consideration for the actual anisotropic consolidation makes the maximum DSM increase up to the value obtained by field test, and the error decreases significantly.

Abstract: In this paper, through the indoor experiment study of compaction characteristics of completely weathered granite improved soil, analyse the relation of the maximum dry density and the optimum moisture content with lime and cement content, and through the fitting working out the relation curves and fitting formula of the improved soil of the maximum dry density and the optimum moisture content with lime and cement content . Provide reference for similar engineering.

Abstract: Rock’s uniaxial compression test is completed and the datum is analyzed, then relationship between loading time and AE amplitude, AE counts sum, AE total energy’s released rate come out. Rock’s critical damage is defined which equal result of one minus ratios of residual strength to critical strength. Based on strain equivalence discipline, damage constitutive models related with acoustic emission characteristic are set up. With damage constitutive models established with AE counts sum and AE total energy serving as damage variables respectively and testing datum, the relationship between rock’s damage and stress and strain is described. Then conclusions come out: 1) damage constitutive model with AE counts sum serving as damage variable manifest rock’s damage increasing process and accords with testing result better; 2) theoretical curve is well consistent with testing curve at rock’s peak strength zone.

Abstract: The system safety analysis method is the foundation to guarantee the safe operation production system. In this paper, all kinds of system safety analysis methods are introduced. Contrast analysis is fully used to grasp the advantages and disadvantages of each method and their application scopes, which will make it better to apply the theory to practice.

Abstract: For the stratum distribution around Taipei Basin, it is typical that the top part of stratum formation is covered in soft or very soft soil with uneven thickness and sits on bedrock with extremely high bearing capacity. For the tall building located at the basin rim, pile foundations are often required due to lack of bearing capacity, as these buildings are sitting on soft or extremely soft soil. When it comes to calculating the bearing or pulling capacity, there are two major ways of calculation, equation of static mechanics and estimation with “N” value from in-situ penetration tests, as specified in the current “Design Code for Building Foundations.” However, the methods mentioned above apply only to general soil, and there is no specific recommendation for the friction and pile tip resistance. Therefore, in foundation pile design, the calculation of friction and pile tip resistance on the part of piles in bedrock is always bothering engineers. Yet, the contribution from the part of piles in bedrock, in fact is significant. As a result, the characteristics of the part of piles in bedrock are a topic worth studying. In this study, pile loading tests at 7 locations at Nangang, Taipei City are taken as examples. Finite element method (FEM) is introduced for simulation of in-situ drilled foundation piles mentioned above that are commonly used. The result of simulation is compared with that of actual static pile loading tests, and it is found that there is consistency between the simulation result and that of loading tests when the bedrock penetration depth of foundation piles reaches 1.6~2.0 times of pile diameter, as FEM is introduced for the simulation of the relationship of axial loading of pile versus pile-head top settlement.

Abstract: The cut-and-fill mining is the main content of the technical system of green coal mining. And it is an effective way for solving the environmental problems and mining the coal under buildings, under railway, under water and over confined aquifer. No matter what kind of filling way, the gob stowing cannot achieve ideal filling effect, the filling effect is random in certain scope. Taking a coal mine as an example, with the aid of stochastic finite element method, the three situations of gob stowing were calculated and analyzed to explore the statistical rule of the ground surface settlement and the stability of surrounding rock because of random variation of gob stowing effect.

Abstract: Rainfall is a key factor that triggers failure of slopes. Due to development of western China, there are more and more slopes with soils mixed rocks, with rainfall effect, some of them will fail, which will lead to loss of life and property. In this paper, a laboratory model was used to simulate to study slope failure of this type under rainfall. Along with rainfall, water infiltrated into the slope, and water content increased steadily and kept almost constant, settlement of inner zone increased with different magnitude and reached almost constant value, and cracks formed on the top, small scale failure occurred.

Abstract: The research of stress wave propagation law under cracked rock has important theoretical value and practical significance. Because of the discontinuity, nonelasticity and nonlinearity of the cracks, the theoretical interpretation and mechanism research about tress wave propagation law are a great challenge to researchers for a long time. From the establishment of the research method, the determination of mathematic model of micro-cracks and the main solutions, this paper brief reviews the current development of the influence of the complicated micro-cracks on stress wave propagation law.

Abstract: Ground source heat pump (GSHP) is an effective energy saving technology for heating and air conditioning. Thermal conductivity of soil is a critical parameter for designing a GSHP system, as the parameter is indispensable in analyzing and determining initial investment, energy saving effects, and operating performance of the system. In this study, the major influencing factors of soil thermal conductivity were analyzed. With different compositions and water contents of soil, the values of conductivity were determined experimentally, which can provide essential data for designing a GSHP system. This template explains and demonstrates how to prepare your camera-ready paper for Trans Tech Publications. The best is to read these instructions and follow the outline of this text