建筑土方工程施工中设计标高的确定

Confirmation of Archtecture Earthwork Project in Construction Design Elevation

建筑土方工程量的大小直接影响工期和成本,施工场地设计标高是确定工程量的重要因素之一。施工场地设计平面考虑泄水的要求应是一个斜面,这个斜面在空间直角坐标系中,主要靠原点标高c、x轴向坡度i_x、y轴向坡度i_y三个要素来确定。为了使总土方量最小、工期短、成本低,应力争使挖、填土方量平衡,核心是场地设计平面上各点的施工高度之和为零。因在求施工高度之和的运算中要出现正负相互抵消,反映不出挖、填方的绝对值之和是多少,故采用“最小二乘法”原理,将各点施工高度平方以后在相加,然后对施工各点高度之和公式中的c、i_x、i_y取偏导数,得出准则三元一次方程组,求出c、i_x、i_y后再求出各点的实际标高和施工高度。

The quantity of construction earthwork impacts the time limit and the cost of the project directly. One of the most important factors to determine the quantity of construction is the ground elevation of the construction field. Due to the consideration of drainage, the plane of the construction field should he an inclined one, which is mainly determined in the X, Y,Z system by three variables - the ground elevation c near the origin, the degree of slope ix on the axis X and the degree of slope iy on the axis Y. In order to ensure the least earth volume, the shortest time limit for the project, the lowest cost of the project and the scooping earth volume equal to the filling earth volume, the sum of the construction altitude of every point on the field must he zero. Hut in computing, the positive construction altitude would be cancelled out by the negative ones, and it could not reflect the sum of the absolute value of scooping and filling earth volume. So we applied the least square method. Firstly, we add up all the squared construction altitudes of every point, and then compute the partial derivative to c,ix,iy. and make it zero. We can gel three -dimensional and simple equation set. Lastly, we can compute the designed ground elevation and the construction altitude after obtaining c , ix, iy.