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Collapse is a typical hazard in highway tunnel excavation process, in order to evaluate the collapse risk level of tunneling activity, the potential loss should be estimated of five severity levels. In this paper, an evaluation algorithm based on the grey clustering theory is proposed, the influential factors of segmental collapse hazard encompass the rock mass classification, distance from the portal,...
In traditional college classes, teachers collect the responses of students via questioning. With the expansion of the student population in China's higher education system, teachers are getting difficult to gather the information on the instruction effect. The importance of Instruction response system (IRS) in traditional teacher-oriented class is getting more and more recognized in college instruction...
In order to research into the fault detection method of bridges, a mathematical model of a simply supported beam with a cracking at mid-span is input with a whitenoise ground motion excitation. The cracking is simulated with gap element, which are able to transfer only longitudinal pressure. Response signals of vertical and longitudinal axial force are analyzed for fault detection purpose, the result...
Risks are widely existing in highway tunnel construction and are related to many influential factors. Based on the analysis of engineering conditions of Maojingba tunnel in Daqing-Guangzhou Expressway, a grey-clustering model is established to evaluate the segmental cave-in Probability level. In this study, six influencing factor, including surrounding rock gradation, tectonics, tunnel embedment depth,...
The strength reduction factor is the key factor in determining design seismic force. The ductility reduction factor, overstrength factor and strength reduction factor of RC frames designed according to current Chinese seismic code are calculated. A method for calculating the ductility reduction factor are proposed based on capacity spectrum method. Nine RC frames with different heights and design...
In the risk evaluation of a highway tunnel, the recognized risk factors are categorized into two hierarchies. The first hierarchy consists of seven items, which are topography, geology, unfavorable geological condition, special stratigraphy, structural design, tunnel section and depth of embedment, shafts and pilot tunnels. An Analytic Hierarchy Process model is established to prioritize the risk...
Rock burst is a phenomenon that the surrounding rock-chip/block blast and disperse under the condition of high stress field or the driving force for excavation in highway tunneling process, exhibited as rocks flaking off from the tunnel wall. By analyzing the influencing degree of rock burst influencing factors, a criterion is proposed to be deployed to predict rock burst risks in the preliminary...
Experiment study on activated carbon preparation from bamboo with chemical activation and by K2CO3 as activating agent was carried out in this paper. The effects of activation temperature, impregnation ratio and activation time on specific surface area, volume resistivity and ash content were systematically investigated. Specific surface area was estimated by BET surface area analysis. SEM analysis...
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