铁路和公路的勘测和定线必须测设横断面。在路线的直线部分,该项工作可用通常的方法来完成;在曲线上横断面的测设较为复杂,横断面应当是曲线半径(法线)的延长线。应当记得,在多山坡地区的路面横断面就连离半径不多的偏差也可能引起断面显著的变化,因而设计土方的计算将不正确。在有关勘测问题的文献中,几乎没有涉及这类问题,同时在实际勘测和修筑道路时,曲线上横断面的测设对钉出椿点和加点有时将引起不少困难。在曲线上横断面的测设通常是由切线或者最好由相当于纵座标Y及К—Х(取自Важеевский,федоров等所编用表)值的点子连接而成的直线来进行,但在这两种情况下横断面方向都有一定的容许误差,而通常只按照半径的大致延 Railway and road surveys and alignment must be measured cross-section. In the straight line part of the route, this work can be done in the usual way; on the curve the survey of the cross section is more complicated and the cross section should be the extension of the curve radius (normal). It should be remembered that even minor offsets in the cross-section of the pavement in the slopes can cause significant changes in the cross-section, so the calculation of the design earthwork will not be correct. Few issues have been covered in the literature on survey issues, and at the same time, it is sometimes difficult for surveys and crossings to be made on the curve to add to and remove from the piles when actually surveying and building roads. The measurement of the cross section on the curve is usually made by a tangent or, preferably, a straight line connecting the points corresponding to the ordinate Y and К-Х (from the tables compiled by Важе вверки, федоров, etc.) In both cases cross-sectional orientation has a certain tolerance, but usually only in accordance with the approximate extension of the radius