The Pavement Type Selection And Structure Design Research Of Laoshan Tunnel

During the early road construction period, due to the shortage of construction fund most of the roads built in mountain areas were built around the mountain, which degraded the road class, prolonged the road length, made waste of large area of infield and had higher energy consuming,more safety problems and damages to environment. With the rapidly increasing of economy, the living quality was improved continually and the construction scale of road was enlarged continually too. The road tunnel was used widely because which could improve the road class, shorten the road length and protect the environment. But the type,structure and material design of the road tunnel pavement didn't have special specification, most of them were designed by experience. so in order to avoid the blindness in tunnel pavement design and direct the construction of the LAOSHAN tunnel, it is necessary to research the design method of the pavement type,structure and materials.First, through investigation and literature search, the chapter analyzed the primary diseases on tunnel pavement and its producing reasons, then summarized the related researches on tunnel pavement structure and material, finally confirmed the researching content and technical route. basing on the summary to the primary tunnel pavement types inside and outside our country, the paper analyzed the influence of the work condition of tunnel pavement to the pavement type, compared the performance differences between cement concrete pavement and asphalt concrete pavement in the built tunnel, and finally selected the pavement type of the LAOSHAN tunnel by gray system theory. According to the research achievements of LTPP about continuous reinforced concrete pavement (CRCP) the paper selected which as the pavement base, and then analyzed the depression-resisting abilities of several tunnel pavement structures.Then pointing to the characteristic of tunnel continuous reinforced concrete pavement (CRCP), the paper researched the design method of CRCP in tunnel, the content included the thickness design, the reinforced steel design and the end fixing equipments design. Meanwhile,the paper calculated the stress in the asphalt concrete layer of the combined pavement with the finite element program, ascertained the reasonable thickness of the asphalt concrete layer, prescribed the asphalt mixture design method with the shear-resist index, and finally analyzed the stress condition on different position when the asphalt layer and the concrete layer had different felting condition.Finally, through the pilot the paper analyzed the construction sequence of the CRCP and its end fixing equipment, and the corresponding quality checking standards.