Applied Mechanics and Materials Vol. 711

Abstract: In order to acquaint the application of geological penetrating radar (GPR) in tunnel lining detection elaborately, the tunnel lining model involving diseases (voids, voids filled with water, zone filled with materials and cracks) has been researched with GPR (equipped with a 800MHz antenna). And on the basis of the finite difference time domain method (FDTD), the 2-D simulation model of tunnel lining with different diseases was established with the software GPRMAX2D for further research in 800MHz and 1400MHz antennae. Comparing the GPR images of the test model and the 2-D numerical model with the actual layout settings in the tunnel lining, the following results can be obtained obviously. GPR is impressible to steel, while the lower rebar is difficult to identify for the double-layer rebar; GPR equipped with a 800MHz antenna is appropriate to monitor the void, while the accuracy of the geological radar method is related to the shape, size, depth and water condition of the voids; the accuracy of GPR is almost 50mm for the 800MHz antenna , while it is 20mm for the 1400MHz antenna and cracks can’t be identify with the 800MHz.

Abstract: In order to study the seismic performance of wall component with double steel plates and infill concrete,three wall components with double steel plates and infill concrete were tested.The deformation performance and failure modes were observed under low cyclic lateral loads with high axial compression ratio.Valuable results were obtained for the hysteretic curves,skeleton curves,rigidity degeneration,ductility and energy dissipation capacity.The results indicate that Stud spacing is the key factor to prevent local buckling of steel plate, Steel plate and concrete stress as a whole;Setting stiffening rib, can improve the overall stiffness, bearing capacity and ductility, but had little effect on delaying wall cracks.

Abstract: On July 9 2013, debris flows occurred around Longchi town with large scale and wide harm, which was a great threat to people's life and property as well as reconstruction work. Debris flow ditch in the surrounding town was studied. This paper focused on loose materials, topography and rainfall characteristics, and explored the formation mechanism of debris flow in Longchi town. The result shows that: a small catchment area in valleys also have the risk of large range of accumulation of debris flow, the debris flow is caused by a lot of loose materials in mountains after earthquake and extreme rainfall. Research results contribute to a better understanding of trigger condition of debris flow after earthquake.

Abstract: Impact drill holes into the pile construction technology is widely used in pile foundation construction job, construction vibrating pile thus to bring the impact of the increasingly prominent on the surrounding environment, the impact of this article on the construction site of a pile of drilled hole pile construction vibration effects on the surrounding environment experiment monitored by the monitoring data analysis found that the peak acceleration increases with distance attenuation occurs quickly, on the basis of analysis of pile foundation construction vibration velocity, frequency, and duration of the impact on the surrounding buildings, it is found that the frequency of vibration velocity with less impact on the housing, the duration of the construction will have an impact. Finally, analysis of the impact acceleration caused by the building structure from the perspective of seismic intensity, vibration intensity was found equivalent vi degree seismic intensity of little effect on the surrounding structures. Furthermore, the greatest impact of vibration on the residential buildings, by the way of excavating vibration attenuation ditch to control effect of vibration is proposed.

Abstract: Grounded on the theory of thin shells and with application of generalized functions elements is solved the problem on critical compressive loading definition of three-layered rectangular plate with limited length through cut. The method of consideration of single limited length cut in parallel of one of rectangular sides in plane is spread on consideration of rectangular hole as four cuts should create the closed rectangular contour, and therefore, are simulating the hole. Due the various selections of approximation functions is proposed to also consider various types of boundary conditions.

Abstract: Geotechnical engineering in large scale is endangered by the karst areas which are close to the engineering. The stability of the tunnels is greatly affected by the sizes and locations of the karst caves. Based on a engineering example, a study of the effects of karst area beneath the tunnel on the stability of surrounding rock is conducted. It can be concluded that the displacement release of surrounding rocks and the distribution of the vertical stress in surrounding rocks are greatly affected by the sizes of the karst caves and the distance between the tunnel floor and the karst cave.

Abstract: Glass has the characteristics of biologically incapable of breaking down, corrosion resistant, suitable for long term storage and use. It has resistance of acid, alkali and salt and stable property. The hardness of the natural stone with the glass is very close , therefore, the waste glass as fine aggregate instead of natural sand to produce concrete is feasible. This paper use ordinary concrete C30 as the research object normal concrete using mixed glass method design, in accordance with the percentage of 0, 50, 100 instead of sand. Three sections and eighteen waste glass aggregate concrete specimens were produced for the cube concrete compressive strength and the axial compressive strength experiments. Through the analysis of experimental data, it suggested that the ratio of glass replacing sand is higher ,the compressive strength and the axial compressive strength are higher.

Abstract: Unixial compression tests have been conducted to investigate the influence of bridge length between two collinear cracks on the specimen strength and fracture patterns. Based on the local connectivity rate of cracks, the evolution of the fracture patterns of the bridge is illustrated. It can be concluded that the sensitivity of the strength to the bridge length is reduced as the connectivity rate, L, is higher than 0.8. The fracture pattern composed of tensile and shear fracture will be induced in rock bridges when the bridges are short. Wing cracks develop well as the distance between prefabricated cracks increases, however, the fracture events caused by the conjunction of the secondary cracks are restrained.

Abstract: This article takes an army’s brick-concrete structure building for example to evaluate the safety of the building effectively. It states the points of on-site test, structural calculating analysis and anti-earthquake evaluation and proposes the reinforcing design plan based on comprehensive Assessment.

Abstract: In order to study the seismic performance of low shear-span ratio composite shear wall with steel plate reinforced concrete,three low shear-span ratio composite shear walls with steel plate reinforced concrete were tested.The deformation performance and failure modes were observed under low cyclic lateral loads with high axial compression ratio.Valuable results were obtained for the hysteretic curves,skeleton curves,ductility and energy dissipation capacity.The results indicate that the elastic stage, Specimen stiffness value is larger, and the stiffness change is basically the same; The specimen into the elastic-plastic stage, cracks have appeared in basic beam and early damage. The junction of steel concrete structure and reinforced concrete structure are prone to failure, which should improve the reinforced concrete shear stiffness in the design.