Research On The Settlement Deformation Characteristics And Calculation Method Of High Ultra Wide Rock Fill Embankment

In recent years, accompanied by the implementation of the western development strategy, the development of economy in western China is speeding up. In order to meet the growing transportation needs, wide highway in mountain and airport runway was constructed increasingly. Due to the large difference of the topography and elevation in mountainous, high embankment is inevitable. With the characteristics of mountain's complex geological conditions, large amount of earthwork and large construction area, the construction of high embankment is difficult. The deformation characteristics and stability control is different from general engineering. To understand and grasp the deformation and stability characteristics of high ultra wide embankment fully is important to guarantee the quality, safety, reasonable arrangement of high embankment engineering. Currently, there is no proven method to calculate the settlement of soil subsidence of filling body itself and ultra wide embankment, particularly simple calculation method applied to engineering. Researching on ultra wide embankment deformation characteristics becomes to be an urgent problem.Firstly, domestic and foreign research status about high embankment are summarized and analyzed based on the literature data. The construction characteristics of high embankment were introduced. Following, the calculation methods of high embankment settlement were summed. And the improved layering summation method and the experienced formula method of high fill were introduced.Secondly, through the airport scene filler He-chi indoor screening experiments to determine the site of filler gradation. After comparative analysis of the oversized material commonly used in reduced scale approach, a similar method to the trapezoidal distribution of filler reduced scale processing was adopted. Then by making a large coarse grained soil triaxial shear strength tests the shear strength index C which stands for sticky knot strength and bite force and ? which stands for angle of internal friction were obtained.Thirdly, based on the existing research, the reasons of the ultra wide embankment deformation different from general embankment were analyzed. According to the shear stress coefficient (the ratio of shear stress and embankment loading) various in horizontal, the shear stress method for determining ultra wide embankment was obtained. The settlement calculation method of surface foundation was work out, and add the compression deformation of high embankment filling their bodies, the surface settlement of ultra wide high embankment was work out. The basic parameters of He-chi airport conditions was obtained through laboratory test and combine conditions data, using the finite element software system to analysis the width, height, soil Modulus, slope gradient and other factors on high ultra wide embankment settlement deformation impact, the critical wide height ratio (3?5) was obtained when wide soil base vary from " deflection basin shape" to " saddle" gradually.Finally, based on field measurement data of post-construction settlement prediction in high embankment, the model parameters of regression prediction was obtained, revealing index (ExcDep2) model could reflect the high embankment deformation of settlement accurately.