In more mature and established neighborhoods, the replacement of buried infrastructure can cause considerable disruption. This is evident when the laterals or services to individual businesses or residences need replacement. In this situation, there may be considerable disturbance to valuable landscaping and inconveniences due to the lack of access to a property with conventional cut and cover replacement options. Pipe bursting offers a unique solution to the replacement of service laterals that allows for minimal disruption to the property under consideration.

To replace a lateral using pipe bursting, excavation is required only at the connection of the lateral with the main distribution or collection line, as illustrated in Figure 1. Additionally, access to the location where the service enters the property is required.

Figure 1: Lateral Replacement Configuration

To facilitate the replacement of the defective lateral, it must first be disconnected from the main line, and preparations made to improve access to the location where the lateral enters the property. In the case of a residential structure, a small area of the concrete floor around the lateral must be removed to increase the available space for the pulling of the new product line into the host. Most lateral replacements are conducted using a cable or chain pulling system as this allows the greatest flexibility for the limited space available. The product pipe is typically of continuous nature and is inserted through from the basement of the residence as illustrated in Figure 2. Since a cable or chain is used in this installation, a winch system is used to advance the bursting head through the host line.

Figure 2: Lateral Replacement Set-up

In Figure 3, a pulley and mechanical leg set-up are used to direct the cable to the surface of the excavation where a winch pulls the cable to burst the pipe. After installation is complete, the line is relaxed to reduce any residual strains from installation prior to reconnection to the main line. Restoration to the site and basement can then be performed.

Figure 3: Lateral Replacement Pipe Bursting

In general, lateral replacements conducted in this fashion can be completed in less time and with less disruption to the owner than conventional open cut methods. This provides a practical and cost effective replacement technique for lateral replacement.