Research Of Algorithm For Entitative Deduction Of Strip Foundation

With computer increasingly used in cost engineering, more and more cost engineers use cost software to calculate the cost of engineering. Now one cost engineer usually has more than one cost software, the fundamental reason for this situation is that we can not find a cost software can calculate the quantity accurately as the style of architecture is very complicated and diversified. Hence, we made a deep research into calculating the quantity of the foundation especially strip foundation.Firstly, a minitype vector graphics system is empoldered with Visual C++ language and Open Graphics Library, and axim setting e.g. function are installed in the system. The system provides a graphic flat for the continued algorithm design, debugging and application.Then, according to the actual situation in engineering, the view that strip foundation's starting point or ending point is the intersection point of center lines of different strip foundations is put forward, so, the deduction part can be classified two situations: overlapping and intersection. Where strip foundations overlap, according to the angle of the strip foundation, the form and the height of the cut surface, the deduction part can be divided into several layers, every layer is a cuboid or a wedge or a cuboid and wedge. Then the deduction volume can be calculated by calculating the volume of each layer. Where strip foundations intersect, if there are three strip foundations intersected at one point, only the deducted quantity of the strip foundation which have not deducted and the other two trip foundations need to be calculated, if there are more than three strip foundations intersected at one point, only the deducted quantity of this strip foundation and the ones which are next to it need to be calculated, so, maybe only one strip foundation's quantity is imprecise, but the total engineering quantity is precise. When calculating the deducted quantity where two strip foundations intersect, according to the form and the height of the cut surface ,the deduction part ban be divided into several prismoids, the bottom and top surface's area can be obtained by the dyadic Boolean operation and the formulas which calculate the area of the cut surface which between the top and the bottom surface, then the volume of the prismoids can be worked out, the total deduction quantity is the summation of these prismoids'volume.In the algorithm, objects of COblist class and CArray class supported well by Visual C++ Language are used for storing data, which makes the single list date structure possible and less memory and running time required. And the most typical algorithms are adopted in order to improve the operating speed.Lastly, the capability of the algorithm is checked by an example and the compare with other two cost software. The algorithm in this paper is better than other two cost software in precision, operating speed and operation complexity. And it can be used as a minitype software to calculate the engineering quantity of the strip foundations of a building.