Tunnels

DLZ has been a part of the design and construction of more than 75 miles of major tunnel interceptor projects through complex geotechnical conditions. These sanitary and stormwater projects require special engineering considerations as the large surface flows require a drop of hundreds of feet to deep storage and conveyance tunnels. Drop structure design, therefore, must carefully consider energy dissipation, avoid air entrapment, avoid cavitation, and provide hydraulic stability.

DLZ tunneling services:

• Subsurface exploration and master planning
• Technical and financial feasibility, program schedule, and cost studies
• Preliminary studies, concept, and detailed designs
• Risk management
• Value management (planning, engineering, and alternatives)
• Plans, specifications, and engineering construction estimates
• Condition assessment and rehabilitation recommendations
• Construction management

We also bring significant experience in micro-tunneling which can be used to minimize disruption of traffic and utilities and to reduce the potential for damage to adjacent structures. Trenchless Technology magazine has named DLZ among the Top 50 Trenchless Design Firm.