Ji Shu Sun

The Study of the Highway Glare Plate Height under Mixed Traffic

At present the highway horizontal curve section of Anti-glare panels with a uniform height, through investigation and analysis, the arrangement of the glare effect is not very good ,under mixed traffic, to analyze the reasonableness of the highway glare plate height,the ighway glare plate heigh of the road sightline safety model is set up , the design speed of 60km / h, 80km / h,anti-glare plate height of model is proven。Concluded，In the combinations of different vehicles，anti-glare plate height ranges between 1.15 and 1.65；By contrasting static line of sight and moving-horizon，in thedifferent velocity, when vehicles travel a critical location, vehicle traffic safety start to receive greater impact. Conclusions can be got,first,vehicles travel in the flat curve sections, according to different traffic, adopt different glare height; When the design speed is 60km / h, if central angle is less than 15 °, vehicles which is traveling on the section is safe; When the design speed is 80km / h, if central angle is less than 30°, vehicles which is traveling on the section is safe.

Experimental Study on the Dynamic Compressive Mechanical Properties of Concrete

Dynamic compressive tests of plain concrete specimens (C30 and C40) are carried out on MTS, with the uniaxial strain rate ranging from 10-5/s to 10-2/s. The impacts of strain rates on concrete strength are studied systematically. The mechanical properties of compressive strength, elastic modulus and compressive stress-strain curve of concrete under different stain rates are also analyzed. The experiental relationships between strain rate and compressive strength of concrete are established. It is found that the compressive strength of concrete increases with the strain rate increasing. Modulus is also showing a growth trend, but the growth rate varies greatly; and the stress-strain curve under dynamic loads is similar to the one under static loads. These research achievements can provide us with a more accurate grasp of concrete actual working conditions and provide some guidance to structural design of concrete. These are important to build the dynamic damage constitutive models, too.

Study on the Vehicle Load of Highway Bridge Based on Measured Data

Vehicle load is one of the most important factors to influence the structural security and applicability of the highway bridge. In this study, in order to learn the situation of the vehicle loads on expressway in recent years, and to provide the basic standard for highway bridge load, collected the dynamic data of nearly 4000 trucks through the traffic investigation of a section of 24 consecutive hours on the expressway in Hebei province. According to the actual survey results for statistical analysis and the principle of equivalent fatigue damage, the model of 5 kinds of daily operation vehicle load was deduced based on the measured data and the fatigue loading spectrum was established. The results of the survey can provide references for the design of the highway bridge fatigue load and fatigue assessment in our province in the future.

Study on the Mechanical Performances of the Insulation Board

The basic mechanical properties of the insulation board in external thermal insulation system are studied in this paper. According to the structure of the board, the relevant tests are designed, which includ the plate bearing capacity, the bond strength, the compressive strength and the flexural strength. The test results show that the security performance of the composite insulation board is high and bonding strength is good, compressive strength is high in the case of meeting the basic technical requirements. Besides, with the increase of the insulation board’s thickness, its flexural strength would increase.What’s more, due to the mesh effect on internal reinforcement, failure process has a certain ductility.

Influence of Heavy Axle Load on Dynamic Response of Semi-Rigid Base of Asphalt Pavement

In order to study the dynamic response law of semi-rigid base of asphalt pavement under heavy load traffic, the viscoelastic system model under heavy load was established based on measured loading pattern and axle load distribution with the finite element software ANSYS12.0. Heavy load traffic effect on the dynamic response of semi-rigid base of asphalt pavement was discussed . The results show that semi-rigid asphalt pavement structure dynamic response value changed with the increase of axle load; time varying regularity of stress and strain was not the same in different directions.

Analysis on the Anti-Glare Plate Setting Distance on Horizontal Curve Sections of Expressway

Glare is one of the most important factors threating expressway traffic safety an night. The most commonly way to prevent glaring night is to set anti-glare plate. Different from the straight sections of expressway, the relationship between the front light of vehicles and the distance of anti-glare plate on the horizontal curved section has some-what changed. Through a lot of tests and finite element simulation, the relationship between the distance of anti-glare plate, horizontal curve radius and anti-glare effect were analyzed systematically. Distance calculation formula of anti-glare plate in horizontal curve sections was revised in this paper. The anti-glare plate distance requirement under different expressway alignment design indexes and its calculation formula was proposed. The achievement was beneficial to confirm the anti-glare effect and improve traffic safety. It can provide us with a reference and a supplement of the specification.

The Application of Dynamic Compaction in Road Bed Handling

This paper described the working principle of dynamic compaction and the main points of construction, Using degree of compaction and deflection, evaluating construction quality based on actual project. we can solve the problem of construction quality of the road bed effectively and the waste of the dust, thus avoiding the environment pollution of waste dust and make a good economic and social profit.

Application of Fault Tree Analysis Method on Hazard Identification in Highway Construction

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.

Finite Element Analysis of Deformation Characteristic for Weak Interlayer Foundation

In accordance with settlement observation data of weak interlayer foundation in The North China Plain, finite element model was made to analyze vertical settlement and horizontal deformation by MIDAS/GTS software. Then, Influence factors of subgrade settlement were studied through changing the fill height, crust layer thickness and compression modulus. The results show that crust layer has the board supporting and closing the substratum functions during the period of loading and a relatively short period after loading. The maximum horizontal deformation occurs in weak interlayer rather than the ground surface. The horizontal deformation increases generally with the increase of the fill height. When the crust layer thickness increase, its settlement grows larger and the settlement of soft soil layer has the decrease trend. The settlement of crust layer and weak layer is decreased with the compression modulus increase of crust layer. It explains that the shell effects of crust layer increase with the compression modulus increase of crust layer.

Effect of Strain Rate on the Compressive Mechanical Properties of Concrete

Concrete is one of the most widely used construction material throughout the world. But the properties of concrete under different strain rates differ from each other greatly. In order to investigate the effect of strain rate on concrete compressive mechanical properties, compressive experiments of concrete specimens (C35) are carried out on MTS, with the uniaxial strain rates ranging from 10-5/s to 10-2/s. The compressive mechanical properties of concrete under different stain rates, which include compressive strength, elastic modulus, peak strain and Poissons ratio are studied systematically. The formulas which can describe the change laws of the compressive properties of concrete under different the strain rates are proposed. The test results show that the compresseive strength and elastic modulus of concrete would increase with the strain rate increasing. The effect of strain rate on peak strain and and Poissons ratio is not significant. These research achievements can contribute to grasp the dynamic properties and build the dynamic constitutive models of concrete.