Commentary
Rock slope stabilization is a generalized term for a wide range of devices or methods used to stabilize a rock face. Based on the specific technology being employed, the unit of measurement can change. Also, the unit of measurement can change based on the governing agency overseeing the project.
While rock slope stabilization is a fairly common geotechnical project in applicable regions, there are few sources publicly available that present detailed cost information. As such, most of the data obtained are from case studies developed after the project’s completion or an Engineer’s Estimate before bidding.
Aside from the cost of the stabilization technologies themselves, other costs may be associated with the stabilization process of the rock slope. Some potential associated costs include the mobilization of equipment, the removal of fallen rocks, traffic control devices, and devices to monitor the rock slope. It may also be necessary to protect against falling rocks, or fly rock in the case of blasting, during the construction process, which will incur costs.
Historical Cost Information
A sample of actual project costs is shown in the table below. Due to the scarcity of sources, some pay items are tabulated from multiple sources which are denoted with a hyphen.
| Pay Item Description | Quantity | Unit | Low Unit Price | High Unit Price | Average Unit Price | No. of Bids | Bid Date | Source/Agency |
|---|---|---|---|---|---|---|---|---|
| Scaling | 550 | HR | $100 | n/a | n/a | n/a | 2006 | Virginia DOT |
| Blasting / Excavation | 15000 / 500 | CY | $20 | $100 | n/a | n/a | 2012 / 2006 | New York DOT / Virginia DOT |
| Rock Bolts | 600 | LF | $80 | $100 | n/a | n/a | 2006 | Virginia DOT |
| Shotcrete | 4200 | SF | $55 | n/a | n/a | n/a | 2006 | Virginia DOT |
| Horizontal Drains | 2754 - 7800 | LF | $10.89 | $14.68 | n/a | n/a | 1983 - 1987 | USDA Forest Service |
| Resin Bonding | 5000 | POUND | $8.40 | n/a | n/a | n/a | 2006 | FHWA & Colorado DOT |
Conceptual Cost Estimating Tool
The conceptual cost estimating tool is intended to be used to develop a preliminary project scoping cost estimate. This preliminary estimate can be based on the typical construction cost item values as contained in the Cost Information product or from user specified cost values when such are known. Users should read and understand the information in Cost Information product prior to using the cost estimating tool. You can download the Cost Estimating Tool to open a cost estimating spreadsheet for producing a preliminary project scoping estimate.