Applied Mechanics and Materials Vols. 353-356

Abstract: Based on analysis of characteristics of earthquake-induced landslides and summary of main factors of controlling earthquake-induced landslides, three main factors which are seismic parameters, topography and landforms features and engineering properties of soil are considered the main factor affecting on earthquake-induced landslides. These factors should be focused on to meet the similitude ratio design of the dynamics of landslide in Shaking table test design. Based on study of dynamic similitude law of landslide, the method of changing model soil specifications is used to prepare the model soil which is in accordance with the maximum shear modulus of prototype soil. Also, the engineering properties similitude of model soil is checked by the method of shear wave velocity similitude. By taking the theory of vibration behavior theory of similarity and dynamic failure similar, the formula of dynamic parameters similitude ratio was got. This formula provides calculating methods using shaking table test to simulate earthquake induced landslide.

Abstract: High-rise buildings, as a result of rapid urbanization in China, become one of popular structure kind. However, there have been few seismic vulnerability studies on high-rise buildings, and few fragility curves have been developed for the buildings. Based on the published data of more than 50 high rises and super high rises, the structural information such as building heights, mode periods, locations and sites, the maximum design story drift ratios, are collected and analyzed. The vulnerability analysis for high rises uses response spectrum displacement as seismic ground motion input, since the structures have comparatively long natural period. Using statistics and regression analysis, the relationship between the maximum story drift ratio and response spectrum displacement is established. Based on height groups and earthquake design codes, the fragility curves of different performance levels can be developed. These curves can provide good loss estimation of high rise structural damage under earthquake ground motion.

Abstract: Catenary action has been regarded as a viable load-carrying mechanism in fire for providing structural robustness to steel framed buildings, and this loading mechanism heavily relies on connection strength and ductility under exceptional loading conditions. However, the current code of practice has no detailed guidance on estimation of the connection ductility. This paper is dedicated to demonstration of how to quantify connection ductility in a fire or non-fire situation through the component-based approach. Connection ductility has been evaluated with emphasis on elongation and strength of connection components in each bolt row, and response of brittle components has been identified as an index for connection ductility and failure mechanism in a fire situation.

Abstract: The fire resistant behavior of web-slotted cold-formed channel columns with non-uniform temperature distributions was investigated extensively by use of the finite element method in this article. The failure mode of the web-slotted column with non-uniform temperature distributions is very complex with the interaction of the local buckling, the distortional buckling and the global flexural buckling. The ultimate strengths of members with non-uniform temperature distributions are higher than that with uniform temperature distributions of the same highest temperature. In addition the analysis results indicate that the degradation of the material strength makes the dominating factor influencing the fire resistance of cold-formed members. The simplified approach was proposed for the practical design of web-slotted cold-formed columns at high temperatures.

Abstract: In order to study the dynamic response of transmission tower equipped with a pendulum damper induced by wind load, a simulation, considering wind load acting on pendulum, is implemented. Deducing the vibration equation of transmission tower-pendulum system induced by wind and utilizing harmony superposition method and Davenport power spectra to simulate fluctuating wind load, time history analysis based on Newmark β step-by-step integration method is conducted to study the influence on displacements of pendulum and tower tip in the two conditions of considering and unconsidering wind load acting on pendulum damper. It can be found that pendulum displacement would be underestimated, and tip displacement would be overestimated if we dont consider wind load acting on pendulum.

Abstract: Used the dynamic triaxial apparatus to test 4 group remodeling silt samples of different fines content. Studies the variation relationship on liquefaction resistance of silt with different fines content.And pore water pressure increase of silt with different fines content is analyzed through Exponential function model,the model parameters can be get. The numerical results show that the model has good applicability.

Abstract: According to the less research on cooling technology and the present complex situation of the heat treatment in capital construction mine, the characteristics of heat damage manage of the capital construction mine are analyzed. The cooling measures are designed in capital construction mine. The comprehensive management measures combining the non-mechanical refrigeration and mechanical refrigeration way, must be adopted in the cooling in the capital construction mine. The non-mechanical refrigeration includes the ways to increase the air quantity, chooses the reasonable ventilation type, doubles lane, uses the double air duct for excavating ventilation, controls heat source and strengthens management, etc. Take the capital construction mine of Zhaolou Mine for example, the mechanical refrigeration is introduced. It turns out that the system operation is effective. The temperature in the heading face is conformance to the procedure requirements.

Abstract: According to the practical condition of 3401 fully mechanized caving face in Dayang coal mine, the relationship between strata behaviors, mining technology and stope gas emission are analyzed through real-time monitoring of the support working resistance, advance abutment pressure and gas concentration of working face. It shows that the change of working face abutment pressure has an obvious effect on the regularity of coal face gas emission. The crest value of gas emission falls behind periodic weighting, the lagging time is about one day. Other factors, like coal production processes, daily coal output and advance speed also have close relationships with gas emission.

Abstract: Researches on structural isolation and mitigation under multi-dimensional earthquake excitations are overviewed in terms of the analysis methods, devices and developing trend. The analysis methods for dynamic responses of building structures, long-span reticulated structures and bridges under multi-dimensional earthquake excitations, are systemically introduced. Several types of multi-dimensional earthquake isolation and mitigation devices are presented, and experimental results of a new type of device are discussed, it shows that the new device has good ability of multi-dimensional earthquake isolation and mitigation. Finally, suggestions for further study in this area are presented.

Abstract: This passage introduced techniques of preventive maintenance that using broad at present, explained the affect factors and principles, and analysis several measures of preventive maintenance and the best time of different conduct of road.