Applied Mechanics and Materials Vols. 193-194

Abstract: The effect of the roadway with no supporting and roadway that was reinforcement by rock bolts and anchor robs, anchor rod combined bolting shoring, anchor rod combined anchor rope and lining timbering was simulated by using numerical simulation software FLAC3D. The results showed that the deformation of no supporting roadway is maximal, and the maximal position is vault. The displacement of top floor and two side decreases after supported, which can reinforce surrounding rock. The reinforcement effect of the anchor rod combined anchor rope and lining timbering is best.

Abstract: Because many accidents in China involve a ship in a barge fleet colliding with a bridge pier, determining the impact force of the ship is important. To obtain an equation that describes the impact force of a ship colliding with a bridge pier, a mechanical model of the collision is simplified, and the results from other researchers are applied. Based on the equation, it is found that the impact force of a ship colliding with a bridge pier is not only relevant to the mass，velocity, board thicknesses of the ship, and the impact angle, but also to the remaining velocity coefficient. It has been demonstrated that the result from the proposed equation in this paper is in accordance with that of Gkss’s test in Wosin G theory.

Abstract: Modeling the dynamic response of the stay cable under bridge deck excitation represents a complex task for cable design procedure and forms an important step in the cable mitigation design. This paper analyses the characteristics of cable response under bridge deck excitation. The problem of cable vibration under the harmonic oscillation of the supports is considered as the external excitation. The formulae for the estimation of maximum amplitude of cable vibration are presented to determine the main cause of large amplitude vibration of the cable under indirect excitation.

Abstract: In practice, the crack in some engineering materials is often compound crack. Therefore, it is important engineering significance to study on fracture problem. Based on the shape change energy near crack tip portion, the area fracture criterion of Iso-εθ line for compound crack was proposed. A crack initiation angle formula and the fracture criterion were established. The results showed that the theoretical predicted values and the measured values are consistent. The compound crack fracture line area of fracture criterion was established.Tthe formulas are easy to be derived and convenient to apply.

Abstract: To design the planning of excavating step on widening engineering of expressway reasonably, three-dimensional finite element method is used to analysis the influence of relative position between load and joint and step thickness combination of asphalt layer on the stress state of widening pavement. It is indicated from the results that step of asphalt layer should be under the marking or middle of the lane. To the double step of old asphalt layer, increase the thickness of lower step can improve the stress state of widening pavement, and joint of base layer step shouldn’t 0.4m away from load. Step planning can affect the maximal shearing stress of joint surface obviously, the index can be use to control construct quality of pavement widening engineering. The conclusion can be use as reference on excavating step for pavement widening engineering.

Abstract: In order to reduce sinking after subgrade construction, impact compaction technology was put forward. The engineering characteristics of Yellow River sandy soil located in Kaifeng, and impact compaction technologies were analyzed. The contrast tests were also carried through, including vibration compaction and impact one. The results show that the subgrade can obtain higher compaction degree with impact compaction technology than the other method, with 2%-5% increasing.

Abstract: Through the axial compression experiment of 11 FRP reinforced concrete columns, this paper analyzes the failure mode and loading-strain curves.Comparison between the experimental data with FRP reinforced concrete and the calculated value without FRP reinforced concrete is done. The results show that the reinforcement for the component will increase ductility and ultimate bearing capacity of the composite column, but the increase of reinforcement ratio will also reduce confining ability of FRP tubes.

Abstract: To investigate the seismic behavior of RC columns under bidirectional lateral loading, numerical analysis for tests of RC columns under biaxial loading were performed using fiber model. The simulation results agreed well with test results. The effect of axial compression ratio on the seismic behavior of RC columns under biaxial lateral load was analyzed. The analytical results showed that biaxial lateral loading had little effect on critical axial compression ratio, and the value of critical axial compression ratio was between 0.4~0.5. Bevel carrying capacity under bidirectional lateral loading was a little greater than that under principal axial loading when axial compression ratio was less than 0.1. There had been about 10 percent decrease in bevel carrying capacity at critical axial compression ratio but principal axial bearing capacity declined about 35 percent. Moreover, ultimate displacement angle and accumulative hysteretic dissipation energy decreased observably with increase of axial compression ratio. The adverse influence of special effect on principal axis should be considered in the actual design.

Abstract: In order to choose a reasonable treatment method for the soft soil foundation, the main factors which affect the soft soil foundation, including technical feasibility, economic rationality and environmental effect, are analyzed. Based on these key factors, a two-level evaluation factors structure for the selection of fare collection pattern is constructed. Taking optimal treatment method as the goal, key factors as attributes, and available methods as alternatives, a multi-attribute decision-making model is set. Under the situation of one case, the model is applied to determine the most suitable treatment method for the case. The best choice is deep mixing pile. The results show that the model is effective and reliable.

Abstract: The process of concrete under symmetric impact was experimentally investigated in the case of primary gas gun and was analyzed .The shock properties of C100 concrete is investigated by gas gun planar impact technique. The manganin pressure gauge is used to measure the pressure-time curves of the samples. The parameters of high-pressure equation are obtained by the numerical simulation. Numerical simulation is a necessary complement to the test. The spall phenomenon is observed by the numerical simulation.