Challenge 

Conventional method for subsurface investigation and geotechnical design of bridge foundation structures is to drill bore holes, retrieve and collect soil samples and transport them to a geotechnical laboratory miles away for testing. This conventional method takes considerable time, resources and exposes the drilling crew and the engineer/geologist potentially, to nearby traveling vehicles.

Solution

The Cone Penetration Test (CPT), technology allows the subsurface characterization and evaluation of the subsurface conditions and soil behavior type without sampling or collecting the soil. Much faster (3-4 times faster) and more efficient than the conventional method of drilling bore holes.  

Result  

• The CPT technology enhances safety of the field personnel during the subsurface investigation. The CT person is in his/her CPT truck and not exposed to the live traffic. This enhancement is more pronounced when the investigation is done during the late evenings and early mornings, which is typically the case in highly urbanized Orange County.

• The CPT technology is much more efficient and faster than the conventional bore hole drilling. (3-4 times faster). This saves time and $ amount. This savings in time and money was instrumental in an efficient delivery of the subsurface investigation for this mega project.

• The CPT technology reduces pollution emission. Since the soil samples are not collected and transported to the laboratory's miles away, thus less travel and less CO2 emission.

• The CPT technology reduces considerably the engineering design time since the subsurface conditions are evaluated directly by this technology and enables the engineer to conduct his/her design efficiently and in a timely manner. No need to test the samples which takes time (days or weeks) for soil laboratory testing.

Project Contact:  

Sharid K. Amiri - Sharid.Amiri@dot.ca.gov