Applied Mechanics and Materials Vol. 470

Abstract: The Chengzigou hydropower station of composite geomembrane rockfill dam as an example of the dam body and the composite geotechnical membrane stress and deformation characteristics are used nonlinear elastic model - Duncan EB model establish three-dimensional finite element model of rockfill,by using the large finite element softwareFLAC^3D,whice provided geogrid element to simulate lexible geomembrane shear interaction with soil.The stress and deformation of the dam and the composite geomembrane is calculated under two conditionscompletion period and impoundment period.And analyze the change of the stress and strain distribution rule,whice will provide the basis for the design of the geomembrane.

Abstract: Electrical equipment such as switchboard should be protected from the seismic hazard to enable stable electric power supply even after the earthquake, since its seismic damage results in the severe damage such as social chaos, fire, and explosion. The general method to secure the excellent seismic performance of switchboards is to reduce the inertial forces by introduction of base isolating systems into a switchboard frame. However, the introduction of base isolating systems may cause the increase of installation and manufacturing costs, which is more true for a low-and medium-seismicity zones, such as Korea. In order to solve finance-related problems, this paper evaluates the seismic performance of switchboards supported by the hybrid springs consisting of wire rope elastic mounts with vertical and horizontal direction stiffness and polyurethane that provides additional vertical stiffness and damping. To do this, this study constructs an analytical model that can properly capture the hysteretic behavior of a hybrid spring. Nonlinear time-history analyses were carried out with floor acceleration time-histories taking into account Koreas seismic design quantities. The analysis results show relatively small deformation of switchboard supported by hybrid springs and high resistance against over-turning moments due to additional vertical stiffness of polyurethane.

Abstract: In this paper, taking a subway station as the design background, combining with the design conditions and the surrounding rock stability, hydrogeology conditions, and using numerical simulation and engineering analogy method, the main structure of the station excavation section is excavated and the tunneling segment supports is designed. Using FLAC3D software to build a subway station tunneling segment model, with reference to the analog out of the design parameters and excavation program, strictly in accordance with the small block and step into the ring principle, the excavation and support are simulated, and the numerical calculation is performed, then from the stress, displacement, plastic zone and other aspects, the station shallow section stability of the support is analyzed, the effect of excavation station bringing to the surrounding soil stability is calculated.

Abstract: According to the existing arch dam design specification, the temperature load is obtained based on analytic solution of infinite long free plate, it only considers the average temperature and the equivalent linear temperature difference of dam section in operation period, the influence of non-linear temperature difference has not been considered. This kind of simplification has some approximation; especially it can not reflect spatial effect of larger temperature gradient changes in the upstream and downstream water level change area. This paper first takes the free plate as an example, has calculated the temperature field corresponding to analytical method, finite element method, standard method, explains the rationality of using written program to carry on finite element analysis. On this basis, take Xiluodu arch dam as an example, the dam temperature load and temperature stress has been analyzed by using finite element method and standard method, the difference between both has been discussed

Abstract: Prestressed cable is an effective way of strengthening. Through the model loading test on the two groups of wood truss, explore the effect of reinforcement to the damaged truss with the prestressed cable. Data show that, in the damage conditions, the bearing capacity of wood truss increased by 112%. Loading test on a group of steel truss, the bearing capacity of steel truss improve only about 12%. The reinforcement effect are different under the same conditions due to the two kinds of material modulus, stiffness parameters are different.

Abstract: Loudness is one of the three basic parameters to assess the auditorium sound quality with reverberation time and balance together, it will be discussed in this paper. There are three expressions evaluating the loudness: listening level, the strength index and the mean forte sound pressure level of tutti-sound (LpF). Each of them has their merits and shortcomings. This paper will focus on these three expressions and the feasibility of checking and accepting acoustics of the hall by loudness.

Abstract: Permanent increase of energy prices leads to the construction of new houses in the low-energy and passive standard. In particular, the development of wooden buildings in recent years has experienced a boom and their positive qualities are coming to the attention of potential investors. Thanks to this the new technologies of construction are still being developed and the new wood-based materials tested. All of these materials and technologies must follow the standards which tightened the thermal technical requirements.

Abstract: With the constant expansion of urban construction, the rapid development of urban underground pipeline becomes complex. Due to disrepair, improper maintenance and management and other factors, the urban sewer appears varying degrees of damage phenomenon. Therefore, the urban underground sewer repair becomes an urgent problem. This article introduces the methods of trenchless pipe rehabilitation technology and developments at home and abroad. It also elaborates the technology design points of stainless steel foam cylinder repair, combining with engineering examples.

Abstract: An analyzing method is proposed to achieve a better study about the energy change which is inputted into a sliding base seismic-isolation system within any range of period during an earthquake. The proposed method is based on the average power index of the input energy into the sliding isolation system, and the corresponding formula are derived. The average power index is numerically estimated and analyzed for the different sliding isolation systems under a varity of conditions with the different duration period and friction coefficient. It is shown that the average input power depends strongly on the friction coefficient, and it can well reflect how much average energy are inputted in the sliding isolation system within any range of duration. So, the analyzing method based on the average power can be well used to study the natural property of the earthquake.

Abstract: Light steel houses are widely applied to low-rise industrial buildings for lightweight, easy industrialization and fast construction. But under the condition of strong wind, there often occurs wind-induced damages to light steel houses because they are sensitive to wind loads, causing huge economic losses. This paper offers a wind-resistant design for a steel structure warehouse which may suffer from force-14 super typhoon with maximum wind speed of 150 km/h. The main factors affecting the wind-resistant capacity of steel structure plants as well as the attacking characteristics and failure mechanism of typhoon on low-rise buildings are fully analyzed. Opinions on the design of low-rise steel structure warehouses against typhoon have been proposed by discussing different wind directions. Considering conceptual design, we also provide some concrete measures of wind-resistance for low-rise buildings in coast areas.