Advanced Materials Research Vols. 838-841

Abstract: Reservoir Induced Seismicity(RIS) is a common phenomenon needed to be focused in the construction and operation of water conservancy project. The Three Gorges reservoir has a digital telemetry seismic network to monitor the earthquakes in this region. According to the correlation between water impoundment and earthquakes, the reservoir induced seismicity can be divided into rapid response and delayed response. The two types can be found in the Three Gorges area as well. In 2003, soon after the first stage of water impoundment, micro earthquake swarm occurred, which is so called rapid response type and water loading is the main factor. And delayed effect is the most observed phenomenon in RIS, in which pore diffusion controls the earthquakes. Double difference relocation results show that the earthquakes can be generally divided into three regions. And the earthquakes controlled by the active faults are called tectonic type RIS, while those related with karst, landslide, etc are nontectonic type. In region A, some earthquakes are related with the Gaoqiao active fault, and some have relationship with karst. The earthquakes in region B are controlled by some coalmines, landslide, and so on. And the earthquakes in region C belong to tectonic type RIS, which have certain relationship with the Xiannvshan fault and Jiuwanxi fault. Different RIS types have different mechanisms and controlling factors, furthermore have different earthquake trending.

Abstract: In order to study the damage characteristics and seismic performances of clear water tanks in water supply system, common damage types and main influence factors are summarized based on the collected damage data, and seismic vulnerability matrix is obtained. Seismic damage loss ratio is suggested by combination damage and construction cost. On the strength of the above results, assessment models of seismic loss for clear water tanks are built, including group assessment model and monomer assessment model. The accuracy and applicability of the models can meet engineering requirements. Finally, anti-seismic suggestions and countermeasures of pools are given based on the above research results.

Abstract: Brick-wood building is one kind of widespread rural houses in villages and town of China, which has potential hazards to people lives and properties during strong earthquake, so that it is necessary to investigate its earthquake damage behaviors. Based on a great many of earthquake damage examples from historical earthquakes, characteristics and mechanics of earthquake damage of brick-wood building were analyzed and summarized. Earthquake damage modes for brick-wood building are mostly horizontal shearing damage, which tends to occur at positions with weak strength in horizontal direction or weak connections between different structures such as walls between doors and windows, intersections between lengthwise and cross walls, bottom of gable, and connections of beam with sommer beams, et al. Brick-wood building generally has better anti-seismic behaviors in earthquake intensity of VII, while worse behaviors in earthquake intensities of VIII, IX and X. Even though, if reasonable anti-seismic techniques and reinforced measures are applied to brick-wood house, it will have better anti-seismic behaviors.

Abstract: While using Fourier Bessel series expansion technique and the coordinate conversion of Graf's addition formula, an analytical solution for the scattering of non concentric arc layered alluvial ancient rivers subjected to plane primary waves was derived. Then the precision of numerical results were checked up and analyzed. Finally, by using the analytic solution, the surface displacement caused by a various thickness covering layer was analyzed under different dimensionless frequency and incident angle. The analysis results show that the crest value of ground displacement is mostly near the ancient river, outside of vertical displacement at vertical incidence which occurred far from the ancient river of incident distal. The various cover thickness have a significant influence on surface displacement. The crest value of ground displacement of non concentric valley is higher than the concentric one at higher frequency incidence in general.

Abstract: Lifeline systems are fundamental engineering facilities for maintaining daily functional operation in cities and developing after-calamity emergency rescue, including power supply system, water supply system, transportation system, communication system, and air supply system. In addition, their damages will influence cities normal operation and residents daily life seriously, which will delay the development of earthquake regions emergency rescue and restoration and reconstruction work. And at the same time, they are significant reasons generating some secondary disasters and important influencing factors causing tremendous indirect economic losses to cities. Therefore, correctly evaluating influences of lifeline system on urban earthquake disaster reduction is an important step for marking the cities ability in reducing earthquake disasters.

Abstract: Using the lateral shift and shift time of reflection coefficient of SH seismic wave at the interface of strata, , we derived and given formulae of normal moveout of lateral shift, discussed the influence of lateral shift on normal moveout of SH-wave, and drawn the curves of normal moveout of lateral shift and the error of normal moveout caused by lateral shift with respect to the angle of incidence. The results show that for glancing wave or angle of incidence being near the critical angle, A large error can be caused by t lateral shift; The error correction of lateral shift should be done before seismic data processing.

Abstract: Using the phase shift of reflection coefficient of SV seismic wave at the free surface of stratum, we derived the lateral shift of total reflected SV seismic wave, given formulae of it, and drawn the curves of lateral shift, The results show that reflected wave of VS-wave exists negative shift; for glancing wave or angle of incidence being near the critical angle, a large error can be caused, In other angle of incidence the lateral shift is the same order of magnitude as the wavelength.

Abstract: Electric power system is an important part of lifeline systems, and it is vulnerable to earthquake. In this paper, the characteristics of failure of electric power system are summarized on the basis of its damages in past earthquakes. Then earthquake damage and failure mechanism of electric structure and equipment are analyzed. Finally, from the aspects of engineering and non-engineering, disaster prevention countermeasures are presented.

Abstract: Landslide is a slope on the soil or rock, subject to erosion of river water, groundwater activity, earthquake and artificial slope and other factors, under the action of gravity, along a plane of weakness or weak zone, whole or scattered along the slope slide down the natural phenomenon. As one of the most familiar and serious danger geological hazard. Slope has caused huge life and property losses of our country and people. So it is necessary to analyze the stable state when facing serious landslide hazards, and giving a reasonable evaluation. Taking Zhouqu Suoertou landslide as an example in this paper, on the basis of investigation and study, general situation of Suoertou landslide is introduced, then the stable state is analyzed, calculated and evaluated, the conclusion is a depend basis for later treatment.

Abstract: Collapse and landslide induced by"5.12" Wenchuan Earthquake generated a large number of loose solid material, which still remained on the mountain. Aftershocks and heavy rain conditions will induce secondary geological disasters, a direct threat to human life and property security and reconstruction results. Based on the landslide of Hanyuan Two Pretty mountain, this paper studied the basic characteristics of landslide before and after earthquake. The finite difference method is adopted to simulate landslide process, and the stress-strain law and failure trend is explored in three conditions including the natural, rainfall and seismic condition. After this, the method of strength reduction is used to analyze slope safety factor in different rainfall conditions. The analytical results are consistent with the macrogeological phenomena before and after earthquake. Research results can provide a reliable basis for the future study of the impact of earthquakes on the landslide and disaster prevention and mitigation.