Advanced Materials Research Vols. 535-537

Abstract: By analysing the cause of frost damages in tunnel, in this paper, the basic principle for prevent frost damage was puts forward. Based on the basic conditions for frost damage occurrence and the extent of frost damage, the grades of frost damage were divided. The prevention measures were made for different grades, corresponding to the concrete engineering application, the waterproof, drainage and insulation technologies were discussed integrally. The results show that, preventing frost damage in tunnel includes waterproof, drainage and anti-frost. Waterproof is the foundation, drainage is the core, and anti-frost is the key. The average temperature of the coldest month, the freezing depth, the occurrence and recharge of groundwater, and the infiltration situation of groundwater were chosen as the control indicators to divide the grades of frost damage into five degrees. In accordance with the different degrees of frost damage, the anti-freezing measures of using center gutter, deep center gutter, thermal-protective layer and drain cavern were proposed. The structure form which uses composite lining and set the waterproof layer between the linings, are not only benefit for waterproof and drainage, but also for anti-freezing. The hard polyurethane plank has good insulation performance and durability, it is an ideal material for anti-freezing and insulation in tunnel.

Abstract: Low-carbon building is the new building types under the background of low-carbon economy. Compared with traditional architectural form, the cost and benefit of the low-carbon building have changed a lot; therefore, it is necessary to analyze the low-carbon building from the perspective of cost and benefit. This paper structured an analysis mode through the cost-effective method, and also provided a new analysis idea and approach to value the low-carbon building, so it has an important referential value for the promotion and construction of low-carbon building in the whole society.

Abstract: A new hydrophobic method of regenerated silk fibroin was introduced here, in which glycerol was used as the inducer. As a consequence, the soluble form of silk was transformed into hydrophobic form, which hence suggests glycerol has a significant effect of hydrophobic induction. Then the morphology and mechanical properties of the hydrophobic silk fibroin was respectively shown by scanning electron microscope (SEM) and strain test. The results showed induced silk fibroin had a compact surface and good mechanical property. Finally, the induction mechanism of glycerol was discussed that glycerol could soften the fibroin’s structure during dry process ,which was the main reason leading to β-sheets of fibroin partly being rebuilt and then the hydrophobic transformation being achieved.

Abstract: The method of CFRP plate reinforcement for the rigid joints with complete welding was studied using finite-element analysis. Three models were adopted in analyzed software ANSYS and they are Solid45, Combin14 and Shell181, which used to simulate steel, glue and CFRP plate respectively. The results show that the ultimate bearing capacity of rigid joints improves significantly after using CFRP reinforcement for joints. And the results also show that the level of improvement is relative to the length, width and thickness of CFRP plates.

Abstract: A new driving device is developed for precise flow control of bitumen foaming. Based on the theoretical studies like fluid dynamics, contact heat transfer, phase change, multiphase flow and turbulent flow theories, a reasonable control model for the bitumen foaming behavior is built. And the CFD simulation analysis of the model with the testing parameters is taken. The results show that the foamed bitumen outlet flow follows the quadratic curve control law with the new driving device.

Abstract: In order to further study the seismic mechanism of ancient timber structure, the wooden structure of the temple was taken as the research object, and the reasonable mechanical model was established by applying semi-rigid spring element to simulate mortise-tenon joint, tou-kung and column base. The test of the compressive, bent and the shear capacity all met requirements by analyzing the model under the static load, and the average safety margin of the structure is 86.7%. The first six inherent frequencies and vibration shapes were obtained by analysing the finite element model using the method of Block Lanczos, With full transient analysis, considered the model in the El-Centro wave, Taft wave and Lanzhou artificial wave excitation under the three earthquake time history analysis, and got the model acceleration time history curves, the results show that the ancient Chinese timber structure has better aseismic performance. The above-mentioned methods and corresponding conclusions could provide the reference for maintenance and protection of ancient Chinese timber structure.

Abstract: Based on the rich previous experimental data, the multi-storey ancient Chinese timber structure shangyou tower of palace style was studied. ANSYS10.0 software was used to establish the finite element models. One finite element model of large wooden frame was established by applying semi-rigid spring element to simulate the joint of mortise-tenon, tou-kung and the connection on column foot in the real wooden structure. The other finite element model of antique building corresponding to the finite element model above was established. The first 10 inherent frequencies and vibrations of the two models were obtained by the method of Block Lanczos with full transient analysis. The model displacement and acceleration time history curves were obtained by taking the two models subjected to El-Centro ground motion, Taft ground motion and Lanzhou artificial ground motion excitation. By the results analysis of the two models, it can be find that the vibration isolation performance of the ancient Chinese timber structure mainly manifests in the column foot, tenon and mortise connection and the tou-kung layer.

Abstract: The overall K6 reticulated shell structure's dynamic elastic-plastic analysis in 9 degrees area under earthquake was researched under different places of Buckling Restrained Braces (BRB) on the shell. The elastic effects of supporting structure and BRB were two key factors. Analysis result shows that it has good performance for energy dissipation on K6 reticulated shell with BRB on both upper and supporting structures together.

Abstract: Removed at authors request

Abstract: Using dynamic elastic-plastic finite element method, on the base of works together and interaction between loess and flexible retaining wall, 3-D nonlinear FEM (ADINA) is used to analyze and discussed the dynamic response of slope protected by soil nailing retaining wall under the EL-Centro and man-made Lanzhou accelerogram. A model that is capable of simulating the nonlinear static and dynamic elastic-plastic behavior of soil is used to model the soil, and a bilinear elastic-plastic model that has hardening behavior is used to model the soil nailing. Friction-element is employed to describe the soil-structure interaction behavior.The results show that the method is safe and credible. The results of the FEM dynamic analysis can be a useful reference for engineers of the design and construction of the soil nailed wall.