房屋施工前首先要定位。目前,常用的房屋定位法有两种:一种是仪器定位法:二是勾股定理法。两个方法的共同点是,根据房屋纵横轴线的交点,定出角桩,然后根据角桩所定出的轴线位置,引到拟建房屋四周的龙门桩和龙门板上。上述作法的缺点是:(1)工作量大,因为第一步要先定角桩,第二步把角桩引到固定装置上,平面越复杂,工作量就越大,相当于放二次线。(2)增加累计误差, Before the construction of the house, we must first locate it. At present, there are two commonly used house positioning methods: one is the instrument positioning method; the other is the Pythagorean theorem method. The common point of the two methods is that the corner piles are determined according to the intersection point of the vertical and horizontal axes of the house, and then lead to the gantry piles and the gantry boards around the proposed building according to the axis position determined by the corner piles. The disadvantages of the above methods are: (1) The workload is large, because the first step is to set the corner pile first, and the second step is to lead the corner pile to the fixed device. The more complex the plane is, the larger the workload is, and the equivalent is to put the second time. line. (2) increase the cumulative error,