利用钻芯孔判断混凝土灌注桩桩身倾斜的分析方法

Analysis Method for Judging the Inclination of Concrete Cast-in-place Pile by Core Drilling

桩基的钻芯法检测可能会出现钻孔偏出桩外的情况,根据钻孔偏出桩外的深度、钻孔的垂直度等信息,可以推算桩的倾斜情况,对指导新钻芯孔的开孔位置,复核桩的可用性等均有重要意义。本文提出了当有两个钻孔偏出桩外时,利用两个钻孔桩顶处坐标及钻孔与桩身边界相交点处坐标推算桩身倾斜的方法。本文分别给出了用于计算桩倾斜方向和角度的方程组及求解该方程组近似解的方法。两种方法可相互校核,可快捷、可靠地进行桩身倾斜情况分析。本文通过一个工程实例演示了分析方法,并介绍了利用孔内摄像法判定桩身倾斜的方位,辅助求近似解的方法。

The pile foundation core drilling method may results in the situation that the drill hole is out of the pile body. According to the information of the depth of the borehole out of the pile and the perpendicularity of the borehole, the inclination of the pile can be calculated, which is of great significance to guide the location of the new borehole and to check the availability of the pile. In this paper, when two boreholes are out of the pile, the method of calculating the inclination of the pile body by using the coordinates at the top of the two boreholes and at the intersection point between the boreholes and the boundary of the pile is presented. In this paper, the equations for calculating the inclination direction and angle of piles and the approximate solutions of these equations are given respectively. The two methods can be checked mutually, and the analysis of pile body inclination can be carried out quickly and reliably. This paper demonstrates the analysis method through an engineering example, and introduces the method of determining the inclination direction of the pile body by means of in-hole photography and assisting to find the approximate solution.