Advanced Materials Research Vols. 446-449

Abstract: To evaluate the capacity and service level of road section under damaged state accurately, it is necessary to study the quantified influence of damaged pavement on headway and average travel speed of road. In this paper, pot hole’s width, rut depth, crack ratio and gap repair ratio were used as the evaluate indicators of the status of damaged pavement. Based on the parameter that surveyed on different level of damaged pavement sections, the affects of damaged pavement on saturated headway and average travel speed are analyzed. It shows that saturated headway and average travel speed are correlated with urban road grade and pavement’s status.

Abstract: Based on the road conditions of the low-grade highway (lower Grade 2) in China southwest mountainous area and speed investigations under different conditions, the estimation model of running speed in this region was established, meanwhile, the criteria for the safety appraisal of line based on running speed in southwest is put forward. Finally, according to the above achievement we developed software for the safety appraisal of line that oriented the low class highway in southern mountainous area in China, and achieve a real-time evaluation of visualization in its design and service life. This method is available for multiple engineering projects.

Abstract: Abstract. Through the analysis and research on the vibration effect caused by the urban New Austrian (shallow embedded) metro tunnel blasting construction, the main harming effect of the blasting vibration on the surface buildings is summarized. According to the actual condition on the site of blasting construction in No.2 line of Dalian metro tunnel, the reasonable vibration monitoring plan for blasting vibration wave is established. At the same time, by means of the regression analysis about the monitoring results of blasting vibration, the vibration wave’s regression formula are set up, which can expression the correlation among the vibration velocity, the charge weight, the distance between the blasting fountains and the buildings. The results show that the Sadaovsk formula can be use to describe the effect of the metro tunnel blasting construction on the surface buildings accurately and reasonably in this construction segment. This kind of regression analysis method can be use to direct subsequent blasting excavation.

Abstract: In engineering project, for a long time due to the particularity, risks and complex organization structure and management modes, etc. Construction safety has plagued the professionals and the general scholars, and highway construction is no exception. To ensure the safety of highway construction projects, hazard identification has become the top priority. Therefore, this paper proposes FTA of highway construction for hazard identification, introduces the basic steps and application process, and explain the application of this method with examples in detail. The application results of fault tree analysis verified this method is scientific and feasible.

Abstract: Using the measured experimental field data of two faults of a rock slope engineering, based on the large number of measured data analysis results of similar projects and rock style to determine the internal friction angle of the fault.the method of how to choose the good date was given. Back analysis method and number fitting method was used to determine the cohesion of fault; anti-slide pile is the lateral force column, the relation of the four failure modes of anti-slide pile was considered. The statistical parameters of resistance of anti-slide pile was calculated by structure mechnics. The norm recommended coefficient transmission method was used to determine function of random variables of slope sliding. The results show that using back analysis method and structure mechnics method to modify the parameter can decrease the uncertainty and improve the reliability of engineering design .

Abstract: TG soil stabilizer was used for sand. A lot of experiment was made. The influence of cement, flyash and stabilizer content to unconfined compression strength were analyzed using orthogonal experiment. It was shown that the ranking of factors influencing 7d and 28d strength of stabilized soil is cement content>stabilizer content>flyash content. TG stabilizer is mechanical property well and simple to construction. It can meet with the demand of pavement base as a new cohesive material in stone lack area. There is good foreground for stabilizer used in highway.

Abstract: Lime soil, literature [1] just gave a general rule to the mixture’s composition design. Because of the soil’s ingredient region difference, the reasonable mix of lime soil in special region must be determined by the test. This paper first quoted the formation of lime soil’s strength and the effect factor, and then regarded the non-side limitation compressive strength at different ages as inspection norm. Used orthogonal design method, the mix for the lime stabilized soil in Jilin area was investigated in this paper. The optimum mix and the main effect factor was determined by the strength at 28 days and verified by the regression strength at 90 days. In the meantime, the key problem had been summarized on the lime stabilized soil construction point and quality control.

Abstract: In the rigid pavement ,seams of joints has been used to prevent damage caused by expansion and contraction of the slab Changes in temperature differences and slab movement. On the other hand always rigid pavement cracks starting and totally starting the failure of the concrete slab are in this region that it has many different causes. In the Place of joints side uses the dowel bar for evidence performance that transfer the forces between slabs to control expansion and contraction changes in slabs. Destruction and deviation in the concrete slab joints side , the high cost of repairing and replacement of dowel bars and the cost of repairing the cracks and the failure of slabs are the reason for re-modeling, analysis and optimization of joints and dowel bar types. In This project, we try to define the role and influence of the shape of dowel bars and optimize the performance of joints in the rigid pavement.

Abstract: In the paper, three–dimension finite element model of asphalt pavement, which includes transverse contraction joint of porous concrete base and asphalt surface, is established for the purpose of studying thermal stress of asphalt surface which is located in transverse contraction joint of porous concrete base. Calculation results of thermal stress are compared with each other. The results show that thermal stress of asphalt surface increases with increase of surface’s modulus, and thermal stress of asphalt surface increases with increase of ratio of base’s modulus to foundation’s modulus, and thermal stress of asphalt surface increases with increase of temperature field of base.

Abstract: Ballast glue is a material to adjust ballast stiffness and stabilize ballast from flying due to high speed train winds; its ballast-glue system is less of microscopic mechanism research. In this paper, 3D DEM method is used to produce sleeper-ballast box model, ballast is made of real size irregular clumps, the ballast glue is represented by bonds to simulate the tensile and shear strength, it works at the ballast-ballast particles interaction contacts physically. The sleeper induced monotonic loadings results show the ballast-sleeper microscopic contact force chain distribution is altered due to ballast glue bonding effects, the glue results in tension forces among ballast system. The ballast-box bearing ability is improved with ballast global stiffness increase; ballast-box global stiffness increases with the glue bonding layer depth non-proportional, and is governed by the top 10cm layer.