Tough Boring Challenge in Northern California

摘要

Upgrading the natural gas infrastructure in Northern California is no small task. It becomes even more difficult when replacing an outdated, unsafe gas transmission line in a stiff clay soil with bedrock near the bottom of the excavation. In this case, the soil was classified as Type B, following the OSHA 1926 Subpart P Standard, and the project called for an excavation running approximately 40 ft long by 14 ft wide and 26 ft deep. It also required boring beneath an existing roadway to upgrade the line.