Study On Construction Quality Control Of Rock-fill Roadbed In High Altitude And Low Temperature Regions Of The West Of China

The roaded,as one of the core components of the whole highway project,plays an important role in achieving the criteria for stability,flatness and durability of the road.Alpine low temperature refers to the high altitude and low temperature.China's high-altitude cold area is widely distributed,poor weather conditions,complex geological conditions,fragile ecosystems,so in this environmental conditions to build highway projects,to take higher and more stringer standards to the quality of the project.When the highway is built in the cold and low temperature of the mountainous area in western China,due to the large pore materials,strong permeability,high shear strength and stiffness of the engineering characteristics of the large,to become China's highway subgrade filling with increasingly frequent materials.The construction quality control of filling stone embankment or earth rock fill subgrade is different from that of traditional filling subgrade.In the actual operation,if the subgrade construction quality control is not targeted,there will be some early quality disease.Therefore,in order to solve the problem of filling stone subgrade in the western region,through the reserch on the method of quality control,using more advanced and more in line with the actual sitiation of the quality control method.Obviously,it is very important to strengthen the control of subgrade construction quality.The construction process of filling stone roadbed in high altitude and low temperature area is complex,which has many influence factors,so it needs to use scientific and reasonable quality control theory and method to ensure construction quality.In this paper,from the characteristic of rock fill subgrade and the special characteristics of cold temperature,analyzes the influence of high altitude and low temperature on the earth rock mixture,construction quality,mechanical performance,working efficiency and ecological environment of the scenic spot.Then by studying the quality control method,compare the characteristics of mass production mode and small batch production mode,and select the basic quality control chart(average-standard deviation control chart)which is suitable for the study of this paper.And by introducting the Bayes theory to improve it,it is concluded that “the small batch control chart” is suitable for the construction quality control of the high cold and low temperature filling roadbed construction.Finally,by combining the qualitative and quantitative methods — the expert investigation method and the gray multi-level comprehensive evaluation method to evaluate the influence factors of the construction quality of the filling stone roadbed in the cold and low temperature.Calculated the porosity,sedimentation rate,gradation,water content,temperature and paving thickness are the key factors that affect the construction quality.Using the improved “small batch control chart” to control the key influence factors of the quality of the subgrade filled in the cold and low temperature area,so as to ensure the construction quality of the roadbed filled in the cold and low temperature area,and to avoid the early quality disease after the work.Finally,based on the construction of the filling stone subgrade of the rolling road in the national Forest Park,the technical control of the gradation,water content,temperature and paving thickness of the key indexes are carried out.And then use the improved”small batch control chart”on the key indicators of the porosity and settlement rate of dynamic management control,check the improved “small batch control chart” in alpine cold region rockfill subgrade construction quality control of feasibility and applicability.