Applied Mechanics and Materials Vols. 90-93

Abstract: In order to make up for defects, including big gravity stress, large mansory and higher ground stress, in traditional gravity retaining wall, a new type of gravity retainwall combining grouting anchor is developed to support higher embankment. By installing soil pressure cells and anchor dynamometric cells, the vertical pressure on the bottom, lateral pressure on the retaining wall and the axial force of grouting anchor are analyzed during filling of embankment.

Abstract: A well-established management system and its corresponding carrier are urgently needed to make engineering construction management achieve such purposes as controlling investment, guaranteeing quality, ensuring safety and shortening construction period. Based on the analysis on the weaknesses of the traditional management model of excavation engineering, the paper introduces the composition and functions of remote monitoring and management system and put forwards with a new model of construction management. Project cases have proven that the management model can improve construction management level and be used by other project management for reference.

Abstract: The existing researches on carrying capacity of passenger stations of passenger dedicated lines basically follow the calculation method for carrying capacity of passenger stations of existing lines. Since passenger stations of passenger dedicated lines are greatly different from passenger stations of existing lines on traffic organization mode, technical operation process and other aspects, researches on these stations should not purely follow the computing method for carrying capacity of passenger stations of existing lines. The research in the paper is suitable for the model of computing the carrying capacity of passenger stations of passenger dedicated lines, and establishing a model for the integrative computing of the peak-hour carrying capacity of the station is the emphasis of the research in the paper.

Abstract: In this paper ,the geostress field of a large area complicated in geological structures was inverted with the stress data of a few measured points by using FLAC^3D numerical stimulation and regression analysis. Two types of models were built. One type is a big model without geological structures, which considered the influence of layer thickness, lithology, stratigraphic dip and ground surface fluctuation first, and then corrected the simulation results according to the measured data, and finally got the geostress field without regional structures by regression analysis. The other type is small regional structure models, which paid attention to the influence of depth, fault type and fault throw, or fold type and fold amplitude, and gained the influence range and coefficients of each geological structure to the geostress field. At last, the results of two types were integrated together, and the large area geostress field under complex geological condition was got. According to this method in allusion to a specific example, the principal stress isoline and vector horizontal projection of coal seam roof including three faults and one fold were obtained, which could analyze the stress magnitude and direction. The method above can solve the problem of how to use the stress data of a few measured points to gain a wide range geostress field under complex geological condition, which could also promote the study of geostress field inversion and have certain engineering application value.

Abstract: A dynamic consolidation model of double layered foundation of saturated soil and unsaturated soil is proposed. Mechanism of dynamic compaction treating on double layered foundation is studied by the model. On the base of the mechanism a new technology called soil-mound dynamic consolidation can be applied to treat the ground of saturated silt and silty clay with high groundwater level. The water-pore pressure test, static cone penetration test, settlement plate test are applied to evaluate that of the new technology with different construction parameters. The treatment effect is more remarkable than that of plastic drain-dynamic consolidation.

Abstract: The nuclear waste storage projects, hydropower and etc are often installed in the hard crystalline rocks. The creep phenomenon of the hard rocks appears in virtue of the complex geological conditions, especially when the excavation brings about damage and cracks to the rockmass, and they largely weaken the hydraulic performances of surrounding rock. Once the excavation-caused cracks are well connected with the native ones together, the engineering safety will be brought great harm to. By dint of newly developed shear-flow-creep coupled experiment system, on condition of the constant normal stiffness boundary conditions, the coupled shear-flow-creep tests are conducted. Not only the tests testify that the equipments is reasonable and effective and the creep largely influences the seepage performance of the rock crack, but also the coupling characters are primarily proved up.

Abstract: Cement asphalt mortar is a key part of flexible adjusting layer in slab ballastless track structure. In this paper, new materials of epoxy asphalt cement mortar (EACM) was prepared with epoxy and chemically modified asphalt emulsionwhich showed excellent in terms of durability and weather resistance. This paper through changing the proportions of the eopxy-asphalt cement ration studies the relationship among fluidity, compressive strength, and elastic modulus of EACM and cement asphalt mortar (CAM) use chemical modification of asphalt emulsion and normal asphalt emulsion. The results showed that chemically modified epoxy asphalt emulsion cement mortar turned out to be relatively better in compressive strength, frost resistance and weather ability compared with CAM. The chemical reaction mechanism of epoxy asphalt emulsion were investigated by the means of environmental scanning electron microscope (ESEM) method.

Abstract: Problem is brought forward by the weak soil layer and the soil near slide surface. The weight back analyzed is presented to solve the problem. For obtaining the weight coefficient, the division of the inclination curve is done. After that, the soil can be divided into several blocks. The displacement of the curve is described by two values: the sliding and the deformation displacement. The method of the weight coefficient calculation is proposed applying the deformation displacement. At last, the sensitivity of the new methods is calculated.

Abstract: Engineering rock mass is commonly a brittle medium containing lots of joints or fissures. Under the stress redistribution in construction，the crack initiation，propagation，and coalescence may cause the strength and stiffness degradation of such medium. And these have an important impact on the stability of rock mass. By employing the analysis software of FLAC3D and improving the constitutive relation, the failure process of the double-cracked rock specimen under uniaxial and two-dimensional compression are simulated and studied. The numerical results match well with the testing results obtained by former scholars. The strength envelope of the jointed rock is obtained as well, and it is applied to analyzing the stability of a slope project.

Abstract: the evolution of rock microdefect is a random variation, and we can consider evolutionary process of microdefect system as nonequilibrium statistic processes. The microbit’s intensity distribution obey Weibull distribution, therefore, this paper adopts Druckr-Prager yield criterion, establishes the damage evolution equation using strain as characteristic parameter under the uniaxial stress, and derives relevant damage constitutive equation. Experiments prove that this equation, to some extent, reflect damage evolution processes under the uniaxial stress.