Advanced Materials Research Vols. 588-589

Abstract: In this paper an old mining goaf in Henan province is studied with the application of 3D nonlinear finite element method. The excavation and backfilling construction and water conveyance operation of the canal upper the old mining goaf is analyzed. Simulation results show that after the grouting strengthening, no layers exceed corresponding strength limit under both canal construction and operation conditions, meanwhile the surface movement and the size of the deformation are within the scope of the standard and won’t affect the construction and safety operation of the canal.

Abstract: Triaxial compression tests have been performed to determine the properties of the rock mass around an unlining underground crude oil storage caverns which is the first one in China. The execution situation of the tunnel project and the seepage law of groundwater are taken into account; the stress and the seepage field around the tunnel in different working states are simulated by applying Comsol around a underground crude oil storage caverns.According to the test results, it was found that the excavation process may arise the local damage,the extension of the excavation induced loose zone ranges from 0 to 15.6 m, depending on the buried depth of the caverns. According to numerical simulation results, the crown settlement and stress concentration is depended on the buried depth and the water pressure distribution after the excavation of the main cavity. This research results can provide the reference for analysis on the stability of the underground cavities under low stress level and on the water sealed underground petroleum storage rock caverns.

Abstract: The research on key technology of mined-out grouting filling management in large channels is carried out based on the geology and distribution characteristic, according to YUZHOU coal mining area on the main channel of the middle rout in the South-to-North water transfer project. This article describes the formula of the goaf governance width, material liquid ratio of filling and sealing grouting, and studies the drilling and grouting technology and then proposes the methods and standards of grouting quality inspection which combines the comprehensive analysis of geological CT scanning, grouting texting and grouting result of data.

Abstract: An extended finite element method (XFEM) for multiple crack growth in asphalt pavement is described. A discontinuous function and the two-dimensional asymptotic crack-tip displacement fields are added to the finite element approximation to account for the crack using the notion of partition of unity. This enables the domain to be modeled by finite element with no explicit meshing of the crack surfaces. Computational geometry issues associated with the representation of the crack and the enrichment of the finite element approximation are discussed. Finally, the propagation path of the cracks in asphalt pavement under different load conditions is presented.

Abstract: Based on industrial CT technique, Meso-mechanical experiment was conducted on construction waste recycled brick to get the real-time CT image and stress-strain curve of brick during the loading process. Box counting method was used to calculate the fractal dimension of the inner pore transfixion and crack evolution. The results showed that lots of pore in the interfacial transition zone mainly resulted in the damage of the brick. With the increase of stress, the opening through-pore appeared and crack expanded, and the fractal dimension increased.

Abstract: Logistic regression model refers a regress analysis contains two types of variants. In geohazard analysis, each geological factor can be defined as independent variable, whether a geohazard happened or not can be defined as a dependent variable. 1 represents an occurrence of a hazard while 0 represents a hazard doesn’t break out. Because those factors aren’t continual variable, lineal regress is inadequate to deduce the relationship of such kind of independent and dependent variable. Therefore using logistic regress method is a feasible way to solve such technique problem.

Abstract: The process of constructing index factors in regional geohazard forecasting is based on profound research and a comprehension of geohazard mechanisms. Taking a geohazard early warning system in Huaying Mountain, China, as an example, principles and key points on establishing those factors are elaborately analyzed and how to quantify them in a system is represented explicitly.

Abstract: For the purpose of investigating the relationship between storey displacements and shear stress as well as the distribution of plastic hinges, the paper treated BRBF as the research object, and on the basis of different horizontal force sharing rate β of buckling restrained brace and the frame strength CB, six models were established, of which elastic-plastic static analysis were conducted with the secondary nonlinear effect. He study showed that storey deformations of the models with horizontal force sharing rates of the buckling restrained braces of 30%-60% mainly occur in the middle and low parts of the frame, for those with horizontal force sharing rates of 90%, the deformations mainly occur in the low parts of the frame, and the storey-concentrated deformation and the distribution of plastic hinge are not affected by the frame strength.

Abstract: In order to research the seismic property of masonry building constructed with the construction waste recycled bricks, a four stories building model with 1:3 scale is constructed and tested on the shaking table. Based on the test results, the cracks pattern, displacement response, acceleration response of the building are studied. The failure mechanism of the infill building is investigated. The results show that the construction waste recycled brick is a qualified building material to construct the low rise building.

Abstract: According to the instance of crosswell seismic in the district of daqing oil, this paper introduces crosswell seismic data acquisition, the processed results, the application of the parameter inversion and geological interpretation in fine reservoir description. Through these examples, this paper also discusses the crosswell seismic technology development status and further development trend.