Applied Mechanics and Materials Vols. 361-363

Abstract: The dissolve settlement characteristics of sulphate saline soil were analyzed by centrifugal simulation test. The results show that the coefficients of dissolve settlement increase with the increase of centrifugal acceleration and are not relevant to salt content. The coefficients of dissolve settlement are very sensitive when the centrifugal force is less than 300 kPa. Its dissolve settlement deformation is the greatest when the content of SO42- is 2.14%.

Abstract: Based on the catalytic effect of trace tin on discoloring reaction of arsenazo M (AsA M) with potassium bromate in 0.08 mol/L sulphuric acid solution, a method for the determination of trace tin by kinetic spectrophotometry was studied. The results show that the maximum absorption of AsA M is at 540 nm and the detection limit of the method for tin is 0.22 μg/L. Beers law is obeyed for tin in the range of determination is 0.7210.0 μg/L. Combined with tributyl phosphate (TPB) chromatographic separation, the method has been applied to the determination of trace tin in rock samples with satisfactory results.

Abstract: In order to check whether the bridge structure is in good working condition, meeting the requirements of carrying capacity and traffic capacity, loading test should be conducted to the Huiketing No.1 Bridge in Mianyang city. The bridge is a double-deck cable-stayed bridge, the upper deck of which works as a footbridge and is connected by 6 chain poles to the lower deck which works as a vehicular bridge. Since the bridge structure is novel, the working stress state is complicated and the coupling effect of the two decks is notable, little referential experience could be found from other bridges. The loading test uses sandbags as equivalent to pedestrian loads on the footbridge and adopts heavy trucks to imitate the design vehicle loads on the vehicular bridge. According to the structural symmetry of the whole bridge and the analysis of its static and dynamic performances in the finite element software, the optimized loading project is finalized. Test methods and analysis results of this footbridge can be used as reference in loading test of similar bridges in the future.

Abstract: Aiming to solve the problem of hard to fill duct completely, the reasons are discussed. Water-cement ratio and admixture are the main influence factors to bleeding rate. There is a minimum grout bleeding rate when water-cement ratio is 0.38 and admixtures are added. The best treatment measure to grout leakage is to flushing out the grout and re-grouting via the on-site grouting test.

Abstract: The installation of horizontal steel tie rod is a critical step during the construction of RC inclined-column bridges. With the aim to ensure the construction safety and to prestress the tie rod accurately, three construction schemes are simulated using the finite element method. According to the simulation, the reasonable tensioning methods are recommended which created a sound theoretical basis to the selection and improvement of construction method.

Abstract: In the research on calculation of interaction of wind and structure, the key to the question is wind field numerical simulation. This paper introduces a practical wind field simulation method of long-span Bridge. The main bridge of Jintang Bridge was analyzed as engineering example, which is a cross-sea cable stayed bridge in Zhoushan of Zhejiang Province , and the linear filter method was applied to calculate along-wind and vertical wind field on main girder, MATLAB program also was adopted to simulate wind field of long-span Bridge. The results show that simulated spectrum is in better agreement with the target spectrum, which verifies validity of the method and correctness of the program.

Abstract: Ramp bridges are usually curved girder bridges, and show unique mechanical characteristics under live load. On the basis of an interchange ramp bridge static and dynamic load test in a radius of 230m, the bridges stress, deflection and dynamic characteristics were analyzed and the bearing capacity was evaluated.

Abstract: Liujiaxia Bridge is a truss stiffening girder suspension bridge which span is 536m, and it is the narrowest suspension bridge with the same scale, so the problems of flutter stability are prominent. Results of wind tunnel test show that its critical velocity cannot meet the requirements without any aerodynamic measures. Based on above considerations, seven kinds of aerodynamic measures are proposed, respectively wind tunnel tests are conducted. The results show that the program, in which the upper central stable board is 1.12m high and the under central stable board is 1.28m high, can meet the requirements. The results of this study provide some references to solving the problem of wind-resistant stability of narrow deck suspension bridge.

Abstract: In order to reduce the potential threat to the Guanyindian highway bridge caused by the damaged RC bridge pier, some damage detection methods including surface inspection, core-drilling test, ultrasonic-rebound test and verticality measurement are used to assess the bridge’s damage condition. The finite element analysis software is employed to simulate the damaged bridge pier and to calculate its bearing capacity, thus providing technical data for the repair and future maintenance of the bridge pier. According to the results of damage detection and calculation, the verticality, the concrete strength, the bearing capacity and the crack width of the damaged No.1 bridge pier could meet the code’s requirement but the damaged regions on the bridge pier need to be repaired.

Abstract: This paper establishes the shape function of high-pier with non-ideal boundary conditions in the top and uses the energy method to calculate its critical load. Then its effective length factor is achieved by using Euler's formula. Further, the FEM and energy method are respect used to calculate the effective length factor of the engineering example and comparative analysis is carried on. Results show that: The non-ideal boundary conditions have great influence on the effective length factor and should be considered in the calculation. The result from the formula of energy method is nearly the same as the one from the FEM which demonstrates this method is of good accuracy to calculate the effective length factor of high-pier. In addition, it is also of great convenience in the design of high-piers.