Three methods are available in our earthworks software ZeonEarth
Normally earthworks softwares will only provide one method of quantities takeoff. Any one of the method list below. But our ZeonEarth which special, it can provides these three methods together. Where it gives user more option in earthworks computation. Therefore, the results calculated can give confidence to user.
It is new method which handles by computer. It is not for human. It needs computer to do such computation. Performance of computation depends on computer hardware. The larger project size will consume more memory and processing power.
The main algorithm of computation is using solid triangulation. It is used to represent the earth surface or part of the surface digitally. The Zeon Earth uses solid triangulation to compute the volume of cut and fill. By using of 3 points in triangle, average heights are compute for existing and proposed levels. Then compute the volume by multiple the average height with area of triangle.
Our Zeon earth is used this methodology to work on. First of all, This CAD drawing is taken from surveyor where all the survey points are shown in CAD. All these points will be existing levels. Then designer need to place in all new proposed level points into CAD drawing. It can as simple as TEXT entities in CAD with specific layer name. Then Zeon Earth will go into CAD drawing to read out all points belong to existing and proposed levels. First task will be triangulate all existing levels. After that, Zeon Earth will reorganize these points to joint all together. All proposed levels which not fall exactly on existing point will be interpolated. It calculates by interpolate the value in one of existing triangle. Later, re-triangulate these points. New triangles will be formed. Finally, each triangle will has two Z levels. One is existing level and the other one is proposed level. Based on three points on triangle, volume can be computed.
For example, surveyor did survey on a site with 5 points. Surveyor will convert these data into CAD drawing. This drawing will then forward to earthworks designer to do earthworks design.
When we want to use this triangulation method, these five points will be connected by line and turn into four triangles. There are many methods to generate these triangles. One of the famous methods is Delaunay Method. For more information on this method, please refer to any document on Delaunay method.
After triangulation, the next step is to determine the proposed levels for these points. As a result, every coordinate will has two Z levels. One is existing level and another one is proposed level. Whenever, levels are identified, volume on each triangle will be determined by using principle below. Each triangle volume will be calculated. Total up all triangles will provide total cut or fill volume.
It is one of traditional method to calculate earthworks. This method is used to obtain the volume of large are of excavation such as basement, housing development and so on where the formation level can be sloping, horizontal or terraced.
The grid method involves drawing a uniform grid onto a plan of the earthworks project, and taking off the existing and proposed ground levels at each node of the grid. With these values the average depth of cut or fill required on each cell of the grid is calculated, and the volume for each cell is obtained by multiplying the depth by the cell area. By adding the volumes for each cell together the total cut and fill volumes for the project can be estimated.
Basically ground and proposed levels are taken at each grid intersection by method of indirect contouring. By reducing the size of square or rectangular, better accuracy in volumes can be achieved. However, the accuracy of results should be determined as the circumstances required for reducing the size of square or rectangular means more work is involved. It will be a signification difference of result by using large grid system compare to small grid system in a hilly area instead of flat area.
An area to be calculated shown with existing and designed levels by contours and platform levels is divided by equidistant vertical and horizontal grids that are known as columns and rows respectively. These columns and rows should be drawn to extend beyond the boundaries of the area so that the whole area is covered by this so called grid system (Figure 2.1).
The columns and row s are then numbered numerically or aphetically from left to right for columns and top to bottom for rows.
Another popular traditional method is cross section method. This method is useful for highway construction projects. They can take a number of difference forms and they are normally based on longitudinal sections. In the construction of a
road, railway, large diameter underground pipeline, having set out the proposed centre line on the ground, levels are taken at regular intervals both along it and at right angles to it to obtain the longitudinal and cross sections.
This is shown on Figure 3.0.
The cross section method involves plotting cross sections of the existing and proposed levels at regular intervals across the project site. For each of the cross sections, the cut area and the fill area is determined. The volume between each pair of sections is estimated by multiplying the average cut or fill area of the two sections by the distance between them.
When preparing the longitudinal section, the vertical alignment is designed and the formation levels along the centerline are calculated. A typical longitudinal section showing the formation level is shown in figure 3.1. Each cross section (CS) is drawn and area between the existing and proposed levels is calculated. Figure 3.1 shows one typical cross section.
Both the longitudinal section and the cross sections are usually drawn with their horizontal and vertical scales at difference values. As with the grid system method, the cross-sections are comprises of total cut/fill section, partial cut and fill as per discussed in grid system method.