Advanced Materials Research Vols. 724-725

Abstract: This article is based on the research on structure safety of the tunnel secondary lining of WU-GUANG passenger dedicated line during service period in China and points out that the dynamic crack of the tunnel secondary lining is the key factor that influences structure safety during service period. This article presents a new method for evaluating the cracking performance of the tunnel secondary lining during service period. The test result shows that new structural materials can improve the anti-cracking performance and structure safety of tunnel secondary lining during service period.

Abstract: In recent years, green buildings have been paid more and more attention. However, in the application, China's green building evaluation criteria still has some flaws. The paper aims at giving a summary of the definition and properties of green building. It is to analyze the characteristics of the current situation of the green building rating standards in our country and in view of our countrys bottlenecks and difficulties in the field of applicability at present, a countermeasure analysis will be made and relevant solutions put forward.

Abstract: In recent years, rigid pile composite foundation has been used as a cost effective alternative to the soft ground treatment of highway and railway in China, but limited studies were conducted on the performance of the composite foundation under embankment load, especially the cushion reinforced by geosynthetics. In this paper, 3 centrifuge model tests were performed and studied on reinforced and unreinforced cushion of composite foundation. Instrumentations were applied to investigate the distributions of displacements, earth pressures in the foundations as well as tensile forces in the model geosynthetics. Following results were found: Cushion reinforced by geosynthetics can not only reduce the deformation of embankment and foundation, but also enhance the load transference to the pile cap from foundation between piles, which means cushion plays an important role in the composite foundation; Cushion works normally because of the geosynthetics in the cushion bearing tensile force. Moreover, the tensile force of geosynthetics below the shoulder of embankment is larger than that in the center of embankment and near the toe of slope because of the lateral restraint of basal reinforcement.

Abstract: Cavity walls structure is unsuitable in cold area for its faultiness of poor heat-insulating property. But the cavity walls constraint masonry construction is suitable in cold area for its high heat-insulating property. Studies are carried as setting up the restoring force model of the cavity walls confined masonry structure and analyzing the dynamic time-history of cavity walls constraint masonry structure under 7 degrees small earthquake, middle earthquake or large earthquake through EL centro wave, TALF wave, Ninghe wave and Qian'an wave, which indicates that cavity walls constraint masonry construction can satisfy seismic demand of 7 degree quake. Finally, the formula for calculating the interlayer displacement of cavity walls confined masonry structure near collapse is put forward and the counting result is compared with that of dynamic time-history analyzing, which shows that the accuracy of this formula is high enough to be used for analyzing the seismic performance of cavity walls constraint masonry structure. Foundation projects: Special Basic Scientific Research for Central Public Institute (2008B002, 2010A04), Open Fund of Key Laboratory of State Education Ministroy on Urben and Engineering Safe and Disaster Diminish & Key Laboratory of Beijing on Engineering Seismic and Treatment (EESR2010-07), and High Level Talent Support Project of Heilongjiang University (HDTD2010-13).

Abstract: Taking a concrete-filled steel tube arch bridge with a span of 80m for example, the paper studies the stability of this bridge by using the general finite element program. The analysis introduces the method to deal with the stability of these bridges by FEM, also demonstrates the result of the eigenvalue analysis and dual nonlinear analysis according to an example. In eigenvalue analysis, the influence of the brace and the X-brace to this arch bridge`s stability are compared under different load cases; in dual nonlinear analysis, the load-displacement curves of three different load cases of the rib failure are given. All of these are some valuable to the stability of the concrete-filled steel tube arch bridge.

Abstract: In this paper, we present a solution without power consumption based on intelligently controlled action of the building external shading facilities, which is provided power supply by the third generation flexible solar cells. The signal, which is measured by wind, light, rain and temperaturesensors, is processed by the Microcontroller Unit system (MCU) controlling the motors of building external shading facilities, and then movement of the building external shading facilities is regulated to achieve the most comfortable of the indoor environment.

Abstract: In this paper, the influence of fly ash with different dosage and grades on the crack performance of airport pavement concrete was studied. Its exercise new Dumbbell Test Method could make the airport pavement concrete material be tested accurately and quickly during early-age from pouring. The effect of fly ash with different grades and dosage on volume stability of airport pavement concrete was evaluated by Dumbbell Test Method. Also the paper analyzes the mechanism of the influence of fly ash on the crack performance of airport pavement concrete.

Abstract: Ballast degradation and unrecoverable deformation are emerged on the railway ballast track under the loads of high-speed and heavy loading locomotive. With the change of tamping frequency, a better understanding of the physics of compactness degree is important for long-time stability of ballast. This paper presented a numerical investigation of the bulk materials dynamics and the transient impaction of a system of irregular polyhedral particles confined with a rectangular box with a retaining wall subjected to cyclic tamping loading. Sphere packing method was being used in this study to simulate typical full-sized ballast particles. This paper aimed to establish firm-soft coupling particle-flow tamping operation simulation numerical model based on contact dynamics theory. This study checked the validity of the model while different tamping working conditions and out-loads was being implemented. The study shows that discrete element method (DEM) is an efficient method to reveal the rearrangement rule of railway ballast after the process of tamping operation.

Abstract: This paper shows the difficulties of the dwellings’ sustainable development in mountain areas on the basis of the fast pace of urbanization and the development of the dwellings in China, in terms of environmental resources, spatial form, regional culture and construction technologies. Then this paper analyzes the application possibilities of BIM on the sustainable dwellings in mountain areas through the discussion of the correlation between BIM and Sustainable Architecture, and proposes the research ideas of design methods.

Abstract: Lining of water transportation channel needs high requirements of crack prevention. The tension stress which results from temperature and other factors during construction is an important reason that causes concrete cracks. Through the simulation of concrete lining during construction period with a section of the middle route of South-to-North Water Transfer Project, it is found that concrete pouring temperature, joint space, cutting joint time always make great contributions to lining crack. Based on calculation results some pertinence measures for temperature control and crack prevention are put forward. Engineering practice shows that effects of these measures are remarkable, which means these measures have significant reference to the concrete lining construction of the same type channels.