Applied Mechanics and Materials Vols. 477-478

Abstract: To explore the regularity of deformation and gas migration of coal seam, the author transmits signal of strain foil on coal samples in all directions by transforming oil plug, oil plug seal, heat shrink tubing and wire seal, based on the existing triaxial seepage device. We can complete coal deformation and gas seepage test with this device under different temperature, different stress, different gas stress and so on.

Abstract: The use of high clay content dredger fill is a popular way to reclaim and create new land for development in coastal areas. In this paper, the dredger fill samples were obtained from 7 locations on the Bohai Sea coast in China. The soils were tested for Granulometric composition, physical composition, chemical composition, and Atterberg Limits. These results are reported. The principle finding shows that the chemical composition of the pore fluids, such as namely problems of drainage and consolidation, has influence on the geotechnical properties of different soils. This work provides the basis for further research on the drainage and consolidation properties of high clay content dredger fill.

Abstract: Propagation rule of acoustic emission (AE) signal in coal and rock is an important basis when AE technique forecasts coal and rock dynamical disasters. Based on correlative theory of quality factor Q, Acoustic emission signal propagation attenuation formula in non-perfect elastic coal and rock are analyzed, Based on the theoretic formula, Effects of different quality factor and propagation distance on AE propagation attenuation are theoretically analyzed ;Based on theoretic analysis results, AE signal propagation numerical simulation and field test programs are designed, AE signal propagation rules in elastoplastic coal and rock are obtained. Field test and numerical simulation experimentation results validate rationality of theoretic forumla. Study production can guide AE technique that forecasts mine and rock dynamical disasters.

Abstract: Passive microwave remote sensing is one of the most effective methods for inversing soil moisture. Under the condition of laboratory, firstly, C band microwave radiation was used to achieve the trial of ground-based remote sensing soil moisture, and then regression analysis was carried out according to the data measured, finally, got the C band experience regression model of soil moisture inversion. The results showed that: in the level-off state of soil surface, soil humidity and soil microwave emission rate is linear negative correlation, in the other words, soil microwave emission rate decreased while the soil moisture increased. Besides, with the increasing of soil surface roughness, both the value of microwave polarization index (MPDI) and microwave emission rate polarization difference Δe have the same trend of quick drop, stabilization and slow raise, and it presented the relationship of quadratic curve with the change of roughness.

Abstract: Calculating the local stress for the anchorage zone of each part in the tooth plate by establishing two kinds of finite element model: considering concrete effect and not considering concrete effect. The result of the comparative analysis of the two models shows that the local stress considering the concrete effect is smaller than that not considering the concrete effect and the maximum difference is about 170 MPa. The difference is not the same in different parts of the tooth plate. Although the design will be tend to be safe for not considering the concrete effect, the size of the tooth plate may increase. Therefore, in order to reduce the weight of the tooth plate , the concrete effect should be taken into consideration in the design.

Abstract: Single pylon cable-stayed bridge with its attractive appearance , economical advantages, become more and more widely. Vertical swivel construction of cable-stayed bridge with steel arch pylon has just begun in recent years. Similar to the construction of Bridges are rare in our country,so many of the key technologies and construction techniques remains to be further research and improvement. This project is to Gaoxin second road single pylon cable-stayed bridge as the engineering background, to research the key technologies of vertical swivel construction.

Abstract: To study the mechanical performance and stability of tied-arch bridge under structural defects and damages, limited element modal of Panzhihua Luoguo Jinshajiang Bridge was established and analyzed. Firstly, some typical damage models and their influence factors were presented. Then, based on the model established, change of suspender force caused by arch rib lineation defect, hanger lineation defect and boom failure was calculated respectively. The stability safety factor under the load group composed of dead load, live load and wind was calculated as well as the second-class nonlinear stability safety factor under structural initial defect. Calculation results shows that, suspender forces were more sensitive to archs vertical defect than to transverse defect. While, short hangers were more sensitive to lineation defect than long ones, and secondary inner force in short booms were bigger than in long ones. The result also tells that lateral wind is bad to lateral stability. Lift wind, somehow, makes positive contribution to structures in-plane stability. Structural initial defect can draw down the second-class stability safety factor under geometric nonlinear condition.

Abstract: Strength experiment on the members tied by PESB and adhesion experiment on the PESB anchored in mortar specimen and in concrete specimen are done in this paper. Through the adhesion experiment, the adhesion strength between PESB and mortar or concrete is detected, which can provide reference for the research on the PESB anchored construction measure. The research results have been applied in practical engineering, from which some suggestion is promoted for the construction of the similar buildings, including requirements on the material used in foaming sandwich wall and notice in construction, construction measure on the PESB tied members and so on. The suggestion will contribute the extension of the energy saving sandwich wall with the on site foaming thermal insulation slurry, which can effectively solve the problem of the duration of the insulation layer in the energy saving walls and promote the scientific process of energy saving from thermal insulation.

Abstract: Whether the design of new structure or reinforcement of the existing projects, structure earthquakereduction design is always the focus of research at home and abroad. The buckling restrained braces won the unanimous endorsement of the engineering sector with good energy dissipation capacity and simpleeasy construction process. This Paper based on the ANSYS analysis the structural response through simulated the bucklingrestrained brace frame structure and the general reinforced concrete frame on effect of the rare earthquake or design earthquake, and analysis the bucklingrestrained braces on the seismic performance of reinforced concrete frame structure. The analysis results show that the seismic performance of reinforced concrete frame with bucklingrestrained braces well, it can effectively reduce the maximum story drift and control structural damage. Therefore, Bucklingrestrained Brace should be used extensively to reinforced concrete framework .

Abstract: Low cyclic loading tests were carried out for one precast two-way hollow slab shear wall with cast-in-situ boundary elements and one RC shear wall. The seismic performance of precast two-way hollow slab shear wall was analyzed. The test results indicated that macroscopic vertical cracks appeared along precast slab vertical holes of precast two-way hollow slab shear wall. The failure characteristics of the precast two-way hollow slab shear wall were significantly different from that of the reinforced concrete shear wall. Shear failure could be avoided and seismic performance of the new type shear wall was good.