门路平纵组合线形(国外英文资料).docVIP

道路平纵组合线形(国外英文资料) The requirement of the line of profile In the design of vertical profile, it is necessary to meet the requirements of the technical standard and consider the comprehensive factors such as landscape. The profile design is designed to combine the terrain and the ups and downs of the terrain, so that it can be coordinated with the surrounding natural landscape and reduce the input cost. Driving from safety, driving comfort and good visual considerations, longitudinal plane alignment design requirements shall comply with the following aspects: (1) ban on consecutive in short sections of concave and convex repeated, avoid to cause wave vision; To avoid the appearance of a linear form that can only be seen closer and farther away, and not to be seen in the middle, to give the driver a sense of security. It is forbidden to set the slope section between the two parallel vertical curves. The two curves should be combined from the same to the concave curve, and the same big curve should be replaced, and the combination of the plane line should be paid attention to the perfect integral effect. The importance of the road line Road lines are one of the factors that affect traffic safety. As the main skeleton of the highway, the road is closely related to highway traffic safety. Road lines include the coordination and visibility assurance of the horizontal aspect. Shall be taken into consideration in the horizontal alignment, curve radius, curve Angle, curve length, easement curve and straight line length, the continuity of linear and horizontal alignment and terrain adaptation condition, etc. In the case of the average accident rate, the accident rate of the curve is three times the line segment, and the accident rate of the road out of the road is four times. There may also be serious accidents involving water accumulation and freezing in the curvilinear segment. In the profile, the slope, the length of the slope and the radius of the vertical curve should be