Kew Gardens Interchange Project Survey to Verify the Accuracy of Construction
SEPC was retained to verify the accuracy of contractor’s survey and the construction based upon it. The horizontal and vertical control traverse was run from controls established by the contractor to bring our random points into system. We performed the survey utilizing the total station and electronic levels and the results were conveyed to the client and the contractor to make needed adjustments. There were three areas that needed information collected as detailed below:
- First area was the outfall area North/West of the MTA railroad bridge at the west/north end of the work area. We were requested to make a topographic study of the two headwalls and the surrounding ground. To accomplish this, we set random control points in areas that could cover the area. We then leveled into these control points from the supplied benchmark information. Once elevations were established, we then performed a gridded topography of the area in question taking invert observations of all observed outflowing pipes.
- Second area of concern was a series of catch basins and a manhole that feed into the outfall areas mentioned above. The same control points used above were utilized in this area. A location of each of the catch basins was made, along with information on the inverts and bottom information was collected. Additionally, the inverts of the main pipes at the catchment structure were taken and immediately reported to on site personnel who utilized them to adjust their plans.
- Third area of concern was the key-walls along the south westerly side of the bridge 11. We were asked to make observations along the top, bottom (on ground), and where visible the bottom of the key wall. An additional set of random points were placed in this area to be used to locate the walls. Elevations on these points were established using the same level run that created those in the outfall area.
