How do you estimate the cost and schedule of a drilled shaft project?

1 Site conditions

The first factor that affects the cost and schedule of a drilled shaft project is the site conditions. You need to conduct a geotechnical investigation to determine the soil and rock properties, groundwater level, and potential hazards. The site conditions will influence the diameter, depth, and spacing of the drilled shafts, as well as the equipment, materials, and methods required. For example, if the soil is hard or rocky, you may need a larger drill rig and more time to complete the drilling. If the groundwater level is high, you may need to use casing or slurry to stabilize the hole and prevent collapse.

2 Design requirements

The second factor that affects the cost and schedule of a drilled shaft project is the design requirements. You need to follow the applicable codes and standards, as well as the specifications and drawings provided by the engineer or architect. The design requirements will determine the load capacity, reinforcement, and concrete quality of the drilled shafts. For example, if the drilled shafts are subjected to high axial and lateral loads, you may need to use more steel bars and higher strength concrete. If the drilled shafts are exposed to corrosive environments, you may need to use special coatings or additives to protect them.

4 Quality control

The fourth factor that affects the cost and schedule of a drilled shaft project is the quality control. You need to ensure that the drilled shafts meet the design and performance criteria, as well as the safety and environmental standards. The quality control will involve testing, inspection, and monitoring of the drilled shafts during and after construction. For example, you may need to perform load tests, integrity tests, or coring tests to verify the load capacity, integrity, or defects of the drilled shafts. You may also need to inspect the drilling equipment, materials, and procedures to ensure compliance and avoid errors or accidents.

5 Risk management

The fifth factor that affects the cost and schedule of a drilled shaft project is the risk management. You need to identify, analyze, and mitigate the potential risks that may arise during the project. The risks may include technical, financial, legal, or human factors that may cause delays, cost overruns, or disputes. For example, you may encounter unexpected site conditions, design changes, equipment failures, material shortages, or labor issues that may affect the project. You need to have a contingency plan, a change order process, and a dispute resolution mechanism to deal with these situations.

6 Project management

The sixth factor that affects the cost and schedule of a drilled shaft project is the project management. You need to coordinate and communicate with all the stakeholders involved in the project, such as the owner, engineer, contractor, subcontractor, supplier, and regulator. The project management will involve planning, scheduling, budgeting, reporting, and controlling of the project. For example, you need to have a clear scope, schedule, and budget of the project, as well as a regular progress report and feedback system. You also need to have a quality assurance, safety, and environmental plan to ensure the project meets the expectations and requirements.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?