Applied Mechanics and Materials Vols. 105-107

Abstract: This paper involves the acoustical design and measurement of sound quality in the new 316 classroom in TYUT. Based on the “Code for design of sound insulation of civil buildings” GBJ118-2010， this paper deals with the acoustical design of the frequency characteristics of reverberation time in the new 316 classroom in TYUT. Before the acoustical design in new 316 Classroom, the measurement of reverberation time (T20, T30, EDT) with frequency 500-1000Hz in empty room are 3.86-4.72s; After the acoustical design that the perforated wooden sound absorption tablet wall within glass wool sound absorption and the gypsum -slab mineral wool board ceiling are mounted in new 316 Classroom in TYUT, the measurement of reverberation time (T20, T30, EDT) with frequency 500-1000Hz in empty room are 0.72-0.82s.Through the checking of the testing data and the evaluation of the users, the acoustical design of the new 316 classroom in TYUT is in accordance with the requirements of Code for design of sound insulation of civil buildings GBJ118-2010.

Abstract: To get environmental action information for structural life cycle design and durability design, the air temperature of Harbin (China) from 1963 to 2002 was employed to analyze the probability distribution of freeze-thaw action herein. The influence of freezing temperature on concrete freeze-thaw damage was taken into account. We analyzed the temperature data of Harbin with an condition of freeze-thaw cycle that the daily maximum temperature higher than 0°C and the minimum temperature lower than -3°C, and the results showed that the freeze-thaw action could obey the half normal distribution well. In addition, applicability analysis of the half normal distribution for different freeze-thaw conditions was conducted as well, and the data can pass the distribution test with a significance level of 0.05.

Abstract: To solve the high-temperature rutting problem of asphalt pavement, the old rubber of the tire rubber and plastic of general polyethylene waste composite modified asphalt mixture is proposed. The plastic and rubber compound particle was made by the rubber through efficient desulfurization additives, pre-swelling, twin-screw extrusion equipment. The particles mixed with the asphalt mixtures specimen preparation and the dynamic stability experiments, composite beam fatigue experiments, flexural tensile strength and modulus experiments and anti-reflective pavement cracks and other mechanical experiments are performed. The comparative data obtained by the rubber and plastic composited modified asphalt mixtures and SBS asphalt mixtures prove that the rubber and plastic composited modified asphalt mixtures have excellent rutting resistance and fatigue resistance.

Abstract: To make a top local adding stories of “L” flat facade irregular frame structure with good resistance to twist and integrity, can better satisfy the requirements of local seismic fortification intensity,using metal damper to this after-adding-stories framework model for processing. Using SAP2000 finite element analysis software modeling and in its install metal damper dynamic time-history analysis before and after. Results show that the structure using metal consumption technology in consume earthquake input energy at the same time can enhance structure rigid and floor wrest resistant and strengthen the lateral stiffness integral structure seismic performance.

Abstract: Load effects and resistance are supposed to constant in traditional reliability theory. In fact, load effects and resistances change with time because some influent factors of structures change in long working life. Thus, only structures are safe at every moment in working life are structures safe. A synthetical method of qualitative and quantitative analysis is proposed in this paper to study the time-dependence problem of a RC free beam. Firstly, the time-dependence character of a free beam is simulated by ANSYS program. Then, a time-dependent reliability model of the free beam is established, and a program is edited to get values of resistance and index of reliability in different years, thus, the time-dependent reliability of the RC free beam is assessed. The results showed that the value of the resistance decreased 20 percent and the reliability index cut half down after 50 years, so time-dependence should be considered to achieve correct results when the reliability of in-service structures is estimated and new structures are designed.

Abstract: This paper discusses the key factors of the dynamic-static drainage consolidation method as it applies to a petroleum storage site that features very soft mud of strength as low as 8.5 kPa. A field experiment was conducted to study the key factors on the success of this method such as effects of the number of tampings and the number of passes. The excess pore water pressures, settlements, field vane strengths were measured. Analysis of the results of measurements at the site leads to the conclusions that this method gives excellent results for strengthening the very soft mud. In addition, for a given total compaction energy, better result is obtained by increasing the number of passes with corresponding decrease in the number of tamping in each pass and limiting the compaction energy at a point for each pass to less than 1000kN.m.

Abstract: Under low stress conditions, when the load exerting on the mined-out areas roof is less than the rock long-term strength, the rock roof will generate some creep deformation. In order to prevent the roof of the mined-out areas suddenly collapse, and to ensure the operator and construction equipment above the mined-out areas safety, it is an important security technical problem to reveal the creep characteristics of the shallow mined-out areas roof. Taking the mined-out areas of Antaibao Surface Mine as background, considering the rheological properties of rock roof, and assuming the roof was a rectangular thick plate, the creep characteristics of mined-out areas roof were analysed by applying the thick plate theory and Kelvin creep model. The regression equation of the roof deflection increment over time was given, and the creep characteristics of the shallow mined-out areas roof were revealed also.

Abstract: It is known that coupled bending and torsional effect is a distinct characteristic of curved girders. According to mechanical characteristics of box girders with corrugated steel webs and theory of box girders, warping normal stress of box girders with corrugated steel webs caused by Torsion Loading is studied. On the basis of second theory of Wu, restrained torsion differential equation of box-girders with corrugated steel webs is proposed. Corrugated webs are assumed as orthotropic plates. Constraint torsional normal stress and shear stress are deduced using Initial parameters method. The results demonstrate that the method is more accurate compared with conventional ones, and it is connected with existing bridge calculation theory. The method is then a practical one in this respect.

Abstract: The strongly weathered rock zone is a special kind of rocks and soils mass. For its larger burial depth and low utilization of natural foundation, the physical and mechanical properties of the strongly weathered diorite were grasped poorly. In the article, the normal investigation together with test in-situ has been applied in the project. The physical and mechanical properties of the strongly weathered diorite were analyzed deeply by the methods of field exploration, laboratory test and testing in-situ. It is feasible for the intensively weathered diorite to serve as natural foundation after lucubrate research and the evaluation of bearing capacity and settlement deformation in the project of the office building of China Industrial and Commercial Bank, Shandong Branch..It is proved from practice that the item of foundation treatment saved about two million Yuan compared with the pile foundation. Moreover it speeded up the process of the construction enormously, lessened the difficulty of the construction and obtained tremendous economic and social benefits.

Abstract: Connection with haunch is a new type of rigid connection. Single and cyclic load test is modeled using the program ANSYS. The result under different axial-compression ratio including hysteretic curve, the energy dissipation coefficient, and the plastic angle on beam ending is ascertained. The hysteretic curve under the ratio 0.3-0.6 is stable, and shows better plastic rotation ability. It exists a limit that axial-compression ratio has an effect on the connection with haunch, the model in this paper is 0.6. With hunch, the node can not only make the relocation of the plastic angle occur, but also increase yield stiffness, ultimate load, energy dissipation coefficient, linear displacement ductility coefficient and the plastic angle of beam end.