Automated route search for pipeline design

Water transmission refers to the transportation of the water from the source to the treatment plant and to the area of distribution. The facility may be realized in three ways, as free-flow (gravity flow), pressurized pipelines (pumping systems) and a combination of them depending on the conditions of the topography, where the pipeline passes through and in terms of the subsequent complex hydraulic processes. Among them, free-flow conduits (canals, aqueducts, and tunnels) are preferred in hilly areas or in areas where the required slope of the conduit more or less coincides with the slope of the terrain. In the free-flow system, the water reservoir placed in the higher elevation of a hill is taken and transmitted to the required place such as residential areas. In the preliminary design of pipeline route, the horizontal alignment design is an important factor in terms of connection of the pipes, which should be realized in certain angles due to flowing and construction goals. Meanwhile, the vertical alignment design, which should provide appropriate longitudinal slopes to perform flow, should be considered simultaneously while planning the horizontal alignment. Although the details of design standards vary with the project area and construction manner, most of the issues involved in geometric design are similar for all water transportation types. Preliminary design is applied to compute the appropriate slopes permitted to free-flow in pipelines used as the most common way of finding appropriate route consideration of the earth topography. This study aims to propose an algorithm automatically connecting two given points for pipeline route preliminary design solutions. The proposed model offers an automatic connection between two ends on a generated terrain due to azimuth angle of the searched points, step interval, horizontal coordinate differences to draw the closest terrain slope as well as to select the more suitable alignment in three steps: First, it compares the slopes between consecutive points and zero-line then selects the minimum difference (with a permissible value). Second, minimum differences in h-value is applied to the results of the first stage as a second criterion (with some permission value also). Third, the shortest distance is applied to the results of the first and second stages as the third and last criterion. This algorithm applied to different digital terrain models including valleys, hills, flats etc. uses negative slopes for free-flow. Moreover, an option for the problematic areas where more than one slope is needed concerning terrain topography to circumvent the lands on which passage is prohibited for any reason (historical, cultural, religious, etc.) and to find the locations of the intermediate points coordinates especially in mountain areas. Consequently, the resulting optimized alignment is non-backtracking, smooth, close to the assigned slope and the shortest path between two points depending on given criteria as much as possible.