Advanced Materials Research Vols. 374-377

Abstract: This paper presents the results of experimental studies on the residual compressive strength of concrete produced with stone-chip as fine aggregates with the compressive strengths of unheated specimen ranging from 45.8 to 129.5MPa after exposure to high temperatures and the experimental parameters being the temperature, admixtures, and PP fiber. Specimens were heated in an electric furnace for 4h to high temperatures ranging from 150 to 960°C. Experimental results showed that the compressive strengths of super high strength concrete used stone-chip (abbreviated to SHSCUS) and normal strength concrete used stone-chip (abbreviated to NSCUS) after exposure to elevated temperatures changed in the manners different from that of normal strength concrete, which reached their peak at about 400°C, and the presence of pp fibers in SHSCUS concrete could reduce the risk of spalling at the high temperatures and the peak value after fire.

Abstract: This thesis is mainly contributed to the study of the complex interface type sorted as traditional architecture located in Western Hunan Province, by using the research methods of architectural typology. Furthermore, I extract its regional type and take the efforts to make typology transformation, and also pay enough attention to the regional expression of the architecture space and interface during the practice.

Abstract: This paper discusses the application of the rammed pedestal pile in thin stiff stratum in soft soil based on the engineering practice, presents the strengthening design of adopting thin stiff stratum as bearing stratum, and provides guidance for the strengthening of thin stiff stratum which has great economic significance on the reduction of engineering cost.

Abstract: According to the philosophy of “partially weaken the core element of the BRB to protect the other part”, 12 specimens of the Triple Square Steel Tube Buckling-Restrained Brace (TSST-BRB) were designed with which the core element had notched. ABAQUS finite element method was used to investigate the performance of TSST-BRB with different notched kinds, number, length and depth of the core element. The analysis results indicated that the core element with annular notch was conducive to reduce the stress concentration of ends, and dissipate energy under tiny displacement. Two notches of the core element were better to reduce the peak stress of the notched segment and the stress concentration of ends. The length of notch should be controlled on 13.3%~20.0% of the length of core element. The energy dissipation capacity, yield displacement and yield capacity of the TSST-BRB were significantly influenced by the depth of notched core element. The depth of the notch should be controlled on 10%~23.3% of the thickness of core element.

Abstract: Shear studs are critical important connectors in steel and concrete composite structures, and they will subjected to longitudinal shear force and transverse shear force, and as well as the tensile force under the applied loads. The mechanical behaviors of the studs are very complicated. In this paper, the spatial finite element model of Xinshiji Bridge, a steel truss arch bridge, was established, and the mechanical responses of the studs under various load cased were analyzed. The calculation results show that the shear forces of the studs under the dead loads are very small due to the structural characteristics of the bridge and the construction sequence of the bridge decks. Thermal effects, especially the effect due to temperature difference, are the key factors for the design of the studs in region near the ends of the bridge decks.

Abstract: Steel and concrete composite structures are widely used in bridge engineering, for it can fully utilize the compression property of concrete and tensile behavior of the steel. However, the coupled behavior of shrinkage and creep exist in concrete. The creep behavior is dependent on the initial stress, while shrinkage is not. The shrinkage and creep of the concrete have a significant influence on the internal force and deformation and it may cause the cracking or even the failure of the structure. Nowadays, precast concrete slab is widely adopted in the composite bridges to reduce the effect of shrinkage and creep. Storage time is a critical parameter for the precast concrete slab to reach the best economic benefit and mechanical behavior of the structure. Therefore, in this paper, the finite element model of Xinshiji Bridge with the consideration of the relative slip between the steel and concrete was established to investigate the influence of loading age of the concrete on the mechanical behavior of the composite bridge, and the optimal storage time was determined.

Abstract: Tailings dam safety has always been an important research field of geotechnical engineering world, and research on safety factor of dam is an important indicator of stability of tailings dams. In this paper assumed that Sweden arc method and simplified Bishop method were used to analyze influence of berm number on safety factor of tailings dam in some condition. Results showed that change of berm number had an impact on total safety factor of dam; Impact of change of berm number on safety factors was also different at different intervals. The influence analysis of changes of berm number on safety factor of dam had directive significance for design and construction on site.

Abstract: Saturated and unsaturated seepage analysises are given for Dashiban Landslide applied multi-day rainstorm once in fifty years including three day and five day and seven day rainstorm. The impaction of rainstorm on the stability of landslide is discussed.

Abstract: First of all, parameter model of bond strength after bolt corrosion is built consideration of the own characteristics of mortar bolt anchorage; second, the whole process of mortar cover cracking is simulated by numerical method using the thinking of interface assembly in mechanical industry for reference; and at last, the results of above two are used to analysis anchor characteristics in anchorage body after bolt corrosion. The analysis result shows that before mortar cover cracking, bond stress increases with the improvement of bolt corrosion ,and the max stress can be obtained when mortar cover begin to crack and after that the bond stress begin to decrease ,the min stress is got just at the time that the mortar cover crack completely. After mortar cover cracking, the peak value of bond strength in bolt-mortar interface and mortar-rock interface will move to deeper place and the distribution of bond stress in effectively anchored length tends to be uniform in high stress level.

Abstract: Frame-bent structure is usually used in the power plants, and in many cases the bent part of it is usually simplified as an articulated bar. To prove the rationality of this simplification, in this paper, two models of one frame-bent structure are built and let them experience earthquake waves from different directions by the mode-superposition response spectrum way, then the shear that each column bears can be calculated .Through the data we get ,the judgment about the rationality of the simplification way can be made