Advanced Materials Research Vol. 790

Abstract: The finite element model of a separately built one-storey underground frame was set up with software ANSYS/LS-DYNA and numerical simulation was done to study on surface overpressure and deformation of the underground frame beam under internal blast loads. It is found that the overpressure peak values on the beam end and middle surface are both much higher when the explosive is below the middle of beam and the peak on the middle surface goes up with the increment of explosive height while that on the beam end surface is not sensitive to the height. The numerical result also indicates that the soil around the frame nearly has no effect on surface overpressure of the frame beam. However, whether there is soil or not the beam deformation has much difference and the increment of the deformation is closely all the same for different soil thicknesses but under the circumstance of thicker soil the beam obtains less deformation upward in a short time after explosion.

Abstract: An underground structure has been in a state of static equilibrium under the combined effect of gravity and the surrounding soils confining pressure before internal explosion occurred, and the blast wave can experience multiple reflections and diffractions in closed space, so the overpressure on the surface of structural members was more complex than that when explosion happened in the open space. In this paper, a finite element model of a closed underground frame structure was established by using the finite element software ANSYS/LS-DYNA. Based on the model, numerical simulation by stages was done to study the overpressure distribution on the surface of the retaining wall. This paper main analyzed the effect of the initial balance stress on the blast overpressure distribution rule and the retaining walls dynamic response.

Abstract: Study of grouting reinforcement to disturbance soft soil caused by large diameter slurry shield construction based on Jiangyin Chengjiang West Road over the river tunnel project. First, Three-dimensional finite element model is created to use the ABAQUS finite element software, considering nonlinear deformation of soil in the numerical calculations. By numerical simulation: horizontal, vertical, vertical displacement trends are in accordance with the measured data; increase the layer E, C, φ values can effectively reduce the settlement of soft soil layer, reducing the soil disturbance. Therefore, through grouting reinforcement of upper soil can reduce soil settlement and get to the purpose of reducing the soil disturbance.

Abstract: In this paper, based on SMP criteria, combination of strain softening of rock material mechanics theory, the after peak friction angle φ for the intermediate variables, the residual strain ε to express the after peak nonlinear elastic modulus E, and finally establish a unified non-linear constitutive model of the rock peak residual stress. Combination Xiao Guanzhuang Eastern Mine typical breakdown rock of diorite triaxial test , get stress-strain curves for different confining pressures by this model. It shows that peak constitutive relation of this study can simulate the experimental results, prove the rationality of the model.

Abstract: The earth pressure behind inclined wall considering the soil arching effects which was decided by two factors, the coefficient and average vertical stress, was necessary to research. Based on the analysis of stress state behind the retaining wall, the unified solution of active pressure and passive pressure was derived and was used to calculate both the magnitude and point of application. According to examples, as the angle of inclined retaining wall increasing which was signifying by , the arching effects would be also increasing which the soil was in the passive limit and be falling which the soil was in the active limit.

Abstract: The paper makes research on the early removal template support-system which is designed for a new template support system Invented by China Construction Forth Engineering Division Corp. Ltd. The system can be widely used inside and outside in a building structure engineering, bridge engineering and the temporary Housing stage erection. Compared to the ordinary steel template support, early removal template support system has more excellent performance advantages and is more convenient in the erection of the dissolution , stable performance node etc.

Abstract: Complex interaction mechanism of pile and soil, pile load transfer analysis is difficult. On the basis of analyzing the load transfer mechanism of the friction pile, using the FLAC3D analysis on the initial ground stress state of equilibrium , axial load under the action of pile axial force and displacement, got the ultimate load bearing capacity of single pile and the stress of the contact surface. Analysis results show that the load and displacement in a certain stage into a proportional relationship. Also shows that simulation is feasible and provide a reliable method for the analysis of pile groups.

Abstract: Take the Shenzhen Nanshan Municipal solid waste incinerator (MSWI) as the object, in total 18 ambient air samples were got. The study analyzed the distribution characteristics of ambient air heavy metals (Cu, Cd, Pb, Cr) and As in the surroundings of the MSWI. The EPA Risk Assessment Guidance for Superfund (RAGS) was used to assess the exposure risk. The results demonstrated that the Pb and Cd value in the surroundings of the MSWI were in the accept level according to the Ambient Air Quality Standards (GB3095-2012); The risk assessment showed that the carcinogenic and non-carcinogenic risks via inhalation exposure in the sorrounding of the MSWI were in the accessible levels.

Abstract: As urbanization accelerates, urban river channels become increasingly important in maintaining urban ecological balance, improving urban landscape and optimizing living environment. City requires sustainable development. The application of ecological principles in urban landscape designs would help identify the most suitable way of utilizing resources and space to lessen disruption of ecological environment and reduce uncertainty of future development [ in hopes of realizing sustainable landscape designs. This paper analyzes existing problems in river channel construction and explores ecological restoration in urban river channel designs on the basis of the analysis of Jiangdongzhi Rive of Hangzhou.

Abstract: The paper analyzes the hourly variation of total solar radiation, total perpendicular incidence and radiation intensity of Hefei region in typical years. The change characteristics of total solar radiation and total perpendicular incidence in Hefei region are discussed in the paper. Chose seven cities in different resource areas and Hefei region and compared with the resource situation of solar energy, the paper discovers the distribution regularity of solar radiation intensity in Hefei region, then points out the solar resources are relatively rich in spite of Hefei is located in common solar resource belt area.