Study On Integrated Drainage System In Road Reconstruction And Extension Widening

With the rapid growth of our state transportation, taffic should be improved constantly.But because of lack of pavement structural design and inaccurate traffic forecasts in the past,most new roads occured structural damage or saturated traffic in the initial period of roads,and have been unable to meet the requirement of vehicles. Accordingly, it is one of urgentproblems that how to widen and rehabilitate roads in order to meet the demands of vehiclesand the traffic, which is necessary for socio-economic development.In expressway reconstruction and extension widening,it is important to drain the water inthe scope of the road. The water damage is very seriously,only setting perfect drainages,canensure the stability of roadbed, good performance of pavement and safety.The problem ofdrainage in process of road widening and rehabilitating,based on the road widening project ofZhengzhou-luohe sections in Jinzhu highway.The main content of this paper is that the effectof different drainage items are simulated by the numerical method,and drainage Items areoptimized by the results of numerical simulation,finally finding the best solution for thisproject.That investigation on field mainly aims at pavement and roadbed’s disease and thedrainage system.The prupose is analysing of disease mechianism and finding out the reason ofexcessive moisture content in roadbed.The paper proposes various drainage options about subsurface drainage of roads,whichbase on the drainage system design for new roads,and opions are optimized by the resultsnumerical simulation with SEEP/W.Under the circumstances, which there is lack of drainage system in the central reserve,thepaper study the central reserve drainage system and propose many different options about it,atthe same time,the paper contrast drainage effect of various drainage options by the numericalsimulation software SEEP/W,and recommend the best Item.It carries on the laboratory test to the subgrade soil and analysis capillary water upwardmovement law.It uses the well-known Canadian geotechnical engineering softwareGeo-studio to module for the two soil capillary water upward movement.Through comparison of software simulation and laboratory test result,we can find the way to estimate themaximum height of soil capillary water by using SWCC.It also studies the factors whichaffect the height of soil capillary water with software simulation.It uses stuffing theory to obtain the gradation of crushed stone and carries on thecapillary water test separately to three kind of different thickness of the gradation.It finds outthe gradation which can cut off the capillary water but also has enough strengh.It alsointroduces the construction technology for the crushed stone drainage layer.It simulates theactual effect of this drainage layer in widening subgrade by using SEEP/W software andanalysis of the effectiveness of this crushed stone drainage layer.At the end of this paper itgives some proposals to synthetic drainage system of the testing road.