The Distribution Of Normal Deviation For Fitting The Plane Linear In Old-Highway And Control In Fitting Precision

Highway design in the new and old way of convergence as well as the used road reconstruction and extension need to understand the plane and vertical alignment of existing roads accurately. However, the original design documents are often not readily available or not applicable,we need to fit the old highway road design parameters of flat linear design. To recover the old road horizontal alignment parameters ,we should point in the mid of old road surface , measuring the mid-point coordinate, processing coordinates data, the old road horizontal alignment of computer-assisted fitting and precise adjusting , fitting accuracy assessing,and so on.The process of computer-assisted fitting include line segment fitting using one-place linear regression equation, dispose the intersection of the circular curve radius and determine the center coordinates, dispose the length of transition curve, determine the type of horizontal alignment, adjust the circular curve radius and transition curve length based on the characteristics of deviation of normal distribution.In this paper, plane alignment fitting and fitted with the old road have 8-type deviation relationship between the relative position. From the 8-type of relationship between the deviation of the relative positions of horizontal alignment and the configuration deviation size and sign about circular curve radius and the transition curve length, 8-type of relationships between the deviation of the relative positions and the distribution of normal deviation, can get the relationship of the distribution of normal deviation and the configuration deviation size and sign about the circular curve radius and the transition curve length. This relationship can fine to adjust the initial fitting of the curve section which fail on the accuracy, finally eliminate the systematic error of fitting to achieve the precision requirement.Combined with the experimental data in old section of G321 state highway plane linear design to fitted 65 plane curve, to debug curves paragraph which the initial fitting accuracy do not meet the precision requirements using distribution of normal deviations. These demonstrated the exactitude of the relationship of the normal deviation distribution and the configuration deviation about the circular curve radius and the transition curve length. And the accuracy of linear fitting plane can be greatly increased when its based on the characteristics of normal deviation. Since the transformation of the old road plane fitting precision linear specification is not clear,In this paper,made to the accuracy of 0.1 meters as the tolerance of the special sections and large sections of the measurement error due to relax the accuracy requirements. After the experimental demonstration and tolerance to the accuracy is reasonable.