Highway Alignment Design And Safety Audit Based On BIM

The highway alignment is a three-dimensional(3D)alignment determined by horizontal alignment,vertical alignment and cross section.In the current highway alignment design,the horizontal alignment design,vertical alignment design and cross-sectional design between the three difficult to achieve dynamic correlation,and this lack of 3D visualization effects.At the same time,alignment design in the case of design specifications to meet the situation,it is still possible because of poor combination of design to form a hidden traffictrouble,and the use of flat sight distance to check the alignment safety of traditional methods to ignore the vertical alignment combination design of the impact can not fully audit the highway alignmen safety.This paper applies BIM technology tohighway alignment design and alignment safety audit,and demonstrates the way and method of BIM technology applied to highway alignment design and alignmentsafety audit.Firstly,based on the Civil 3D platform,the design method of highway alignment is studied and the engineering application is carried out.Secondly,the VBA language is used to develop the speed calculation program on the Civil 3D platform.Finally,by analyzing the traffic condition of the vehicle in the highway BIM 3Dmodel,Based on the two points of the visibility principle of space,the analysis calculation method of the 3D sightdistanceis obtained.The main contents and achievements of this paper are as follows:(1)Analyze and compare the differences between BIM technology and CAD technology,analyze and compare the core modeling software of BIM,select Civil 3D as the modeling platform of highway design;analyze the highway alignment safety audit method,select the coordination of operating speed and the consistency of design speed as analignment safety audit index;Civil 3D as a secondary development platform to run operating speed as the core content of the run speed calculation program development content and the proposed function was analyzed.(2)This paper studies the design of the highway BIM model by using the the intersection point method and the element method to design the horizontal alignment?using pull slope to design vertical alignment andusing subassembly composer(SAC)to design the cross section,and summarizes the principle and process of creating the highway BIM model.Based on the Civil 3D,a highway BIM model with dynamic correlation characteristics of horizontal,vertical and cross section3 Dalignment was constructed.(3)The VBA language is used to develop the operating speed calculation program,which mainly includes: data read/writemodule,unit automatic segment module,operating speed calculation module and chart output module.According to the calculation results of the operating speed and safety audit index,the alignment safety of the new highway project in the Yunmen C section is audit.Based on the visualization characteristics of the BIM model,the specific situation of the bad design of the alignment is analyzed and the comprehensive measures are put forward.(4) This paper studies the difference between the operating speed and the design speed,and use the operating speed as the calculation index of the sight distance.The position of the driver's viewpoint is set by analyzing the driving condition of the vehicle in the highway BIM model.The 3D sight distance calculation method of the highway is obtained,according to the engineering application,the safety and security measures of the poor sight distance section under the operating speed are put forward.