Advanced Materials Research Vols. 250-253

Abstract: Granite residual soils are often used as compacted soils in engineering structures such as pavement, embankments and backfills in Xiamen. Many geotechnical problems such as bearing capacity, lateral earth pressures and slope stability require an assessment of the shear strength of soil. Since the geotechnical properties of residual soils are impaired in contact with water, a series of unconfined compression tests are carried out on granite residual soils. Results of tests include effects of degree of compaction, moisture content, degree of saturation and cyclic wetting and drying on unconfined compression strength respectively. The increase in degree of compaction and compacting effort increases unconfined compression strength and the former greatly affects the strength. Moisture content of soils is higher than the optimum one of 2.5% for high strength and it is lower than optimum one of 2.5% for good plasticity in Xiamen areas. The degree of saturation of high unconfined compression strength normally ranges from 64% to 76%. In addition, cyclic wetting and drying causes loss of unconfined compression strength and the maximum loss commonly occurs at the first cycle and then is slowed down by the following cycles till the strength remains approximately constant.

Abstract: On the basis of the time-adjusted effective modulus method (AEMM method) and the steel influence coefficients, the combined influence coefficients of the concrete beams strengthened with FRP is proposed. It will have a higher numerical accuracy if the initial stress is substituted with the average stress of concrete and the stress is assumed to remain linear with time during the period in the step by step calculation process. The linear incremental calculation method based on the idea of the creep combined influence coefficient method of concrete beams reinforced with FRP is proposed, which provides a theoretical basis for the creep calculation and long-term stress prediction for an un-cracked concrete beams reinforced with FRP.

Abstract: According to the complex mining geological condition of Shandong gentle inclined multi-seam mining, Use the three-dimensional finite element numerical analysis software to establish three-dimensional geological model under the different mining working conditions. Taking into account the impact of faults to calculate multi-seam roof strata movement and surface subsidence caused by the different mining working conditions. The level displacement & subsidence distribution curve of the reference point of surface & multi-seam roof strata under the different working conditions is shown. The maximum, minimum settlement, differential settlement and subsidence diagram is shown. And the principal stress, shear stress value of surface & multi-seam roof strata after mining also is shown. The results showed that: little change of the biggest surface subsidence and differential settlement is caused by mining 3101&3102 face or separate 3101 or 3102 face. And the largest subsidence, and the settlement difference of the surface is 520mm, 498mm, 515mm and 59mm, 78mm, 81mm, Respectively. It provides an reference for reasonable, safe, economic for the inclined multi-seam mining under similar conditions.

Abstract: Based on the theory study of stress characteristics of the H-beam with corrugated web under transverse load, optimization analysis was conducted. The optimization analysis focused on the corrugation configuration of web, by which one optimized dimension was put forward. To verify the optimization result, total 10 specimens are tested. From the results, the optimization configuration can provide relatively high shear strength and ductility property, with low steel usage. So it can be put into production practice.

Abstract: Based on AMESim，a method of dynamic characteristics analysis and optimization for hydraulic system of a self-propelled steel bridge (SPSB) is presented. The approach of this work includes steps of (1) modeling the hydraulic system by defining components and their parameters according to working conditions; (2) evaluating control modes of the system, testing performance of components and analyzing main factors causing load-impacted and movement-unsynchronized of cylinders in the system by repeated changing and running of the model; and (3) improving the system. The results of this research show that sudden change of piston-rod movement and fluid pressure in hydraulic cylinders could lead to larger load-impacted of the system, and fluid pressure loss and load change of hydraulic cylinders would greatly effect on stability and synchronization of the system; but accumulators installed in the circuits can effectively decrease load impact and enhance movement steady of cylinders, and proportional valves used to control the circuits can obviously improve synchronization performance of cylinders.

Abstract: In recent years, Building Integrated Photovoltaic (BIPV) system has been becoming one of most important application of solar energy. Heat is the key of the BIPV design. If the temperature of photovoltaic modules is too high, it will affect the efficiency of solar cells, the structure performance of the components and service life. This paper present a photoelectric-thermoelectric (PV-TV) model which can collect heat from the solar panels so that to reduce its surface temperature, and then to generate electricity by using of temperature difference technology and devices. The model presented in this paper provides designers a new concept in BIPV design.

Abstract: The matric suction has very important influence on the characteristics of unsaturated sand; and it is closely relevant to density. In order to discuss the relationship among the matric suction, water content and dry density, the matric suction of the eolian sand were measured in laboratory. The soil-water characteristics curves for unsaturated eolian sand with different dry densities are obtained. The test results show that the variation tendency of soil-water characteristics curves has been corresponding to the different densities.

Abstract: Side slop losing stability is one of the main factors which greatly influences freeway expedite construction, especially after side slop losing stability the determination of rock and soil mechanics parameter may take a long time. Inversion method to analyze slope stability can preferably solve the problem. During the treatment of the ecological freeway landslide, we can not obtain important Parameters due to great disparity of sample Parameters of landslide. However, using inversion method to get cohesion and internal friction Angle, and anglicizing its sensitivity during calculation of stability can identify reliable Parameters. According to slope stability calculus, the ecological reinforcement design scheme come into effect.

Abstract: In this paper, the splitting tensile strength experiments of recycled sintered brick-tile concrete with different water-cement ratio, sand rate and water quantity were carried out, and the change law of splitting tensile strength with above three factors was acquired and failure patterns of the samples were analyzed. The results showed that the effects of sand rate and water quantity were not clear, while water-cement ratio was relatively significant and the splitting tensile strength was inversely proportional relationship with it. And the relation between the splitting tensile strength and the cubic compressive strength was summarized from the results.

Abstract: High rise structures with strengthened stories are widely used nowadays. A rational seismic design procedure for this kind of structure is thus necessary. Based on mode theory and direct displacement based seismic design of multi-story buildings, this paper proposed a new direct displacement based seismic design procedure. In the proposed method, each mode of the high rise structure is equivalent to a single degree of freedom (SDOF) system. Seismic response of each mode is calculated and adds up to consider the contributions of higher modes. Considering the characteristic of strengthened stories, two stories above the strengthened stories are taken as the “key stories”, whose performance indicates the performance of the building. The proposed procedure is logical, simple and can serve for reference of actual design.