Trenchless construction projects vary widely in terms of size, budget, and schedule. However, as with all construction projects, successful execution is heavily dependent on adequate planning and preparation.

A study comparing the performance of various projects in the construction industry shows that well-planned projects were likely to be completed at 3% below budget. In comparison, poorly planned projects were likely to be completed at 13% above budget.

Another study by Hamilton and Gibson (1996) found that the top one-third of construction projects from a planning completeness perspective had an 82% chance of successfully meeting project goals compared to 66% of projects in the lower third.

These staggering statistics highlight the importance of project planning and preparedness in the trenchless technology industry.

In this article, we will outline some of the crucial steps involved in planning a trenchless project to ensure that project goals are met on time and within budget.

Define the Scope of the Trenchless Construction Project

Clearly defining the scope of work is the first, and perhaps the most important part of planning a trenchless construction project. The key to developing a well-defined scope is an in-depth understanding of the client’s project requirements.

Once the requirements of the trenchless project are understood, construction managers can outline the scope of work required to successfully meet the client’s objectives.

This scope is ultimately used to help determine the work tasks the contractor will be required to perform, which in turn forms the framework for various activities, including:

  • Construction scheduling.

  • Sequencing of construction activities.

  • Determining resource allocation requirements.

  • Cost estimating.

One of the other advantages of defining the scope of a trenchless construction project is the ability to establish clear boundaries. In other words, trenchless construction teams can determine how and where to perform work while avoiding additional work outside the original job description.

This phenomenon, known as scope creep, can ultimately have significant adverse impacts on the project schedule and overall budget.

Gather Relevant Design Documentation and Project Information

Another crucial component of planning a trenchless project is gathering all the necessary project information. A successful trenchless project needs to consider various elements including, but not limited to:

  • Site topography.

  • Soil data.

  • Existing site structures and infrastructure.

  • The location of existing utilities.

  • Site accessibility.

  • Dewatering requirements.

One of the most crucial reference documents during construction in and around soils is the geotechnical report. Since trenchless work takes place underground, in-depth knowledge of the soil characteristics and properties is paramount.

Several factors, such as the soil bearing capacity, shear strength, moisture content, and groundwater conditions are useful in determining how the installed pipes or utilities will interact with the surrounding soil.

Geotechnical reports are the output of various site investigations conducted by a geotechnical engineering team prior to the start of trenchless activities.

Other information, such as existing utility plans and site surveys, should also be obtained to determine the presence of any obstacles that may affect the progress of the project.

Determine Appropriate Technologies, Construction Methods, and Resources

Once the scope and site conditions are determined, contractors are now in a better position to determine the most appropriate trenchless technology, equipment, and resources needed to meets the client’s job requirements.

For example, for a particular pipeline or utility installation at a given site location, a contractor may determine if horizontal directional drilling (HDD), microtunneling, or pipe jacking is the best suited trenchless method to be employed.

Similarly, if the job involves pipeline rehabilitation, pipe bursting, sliplining, or cured-in-place pipe lining may be chosen depending on the job requirements and the site data.

Consider Safety Planning and Disaster Preparedness

While many trenchless technologies inherently reduce the exposure of workers to hazards, like many other construction activities, they possess risks that must be controlled or eliminated.

It is, therefore, imperative that the construction management team identify all hazards associated with the job site.

For example, the entry and exit pits excavated during pipe jacking, pipe ramming, and HDD must be stable and safe enough to accommodate work personnel.

Based on geotechnical input and OSHA guidelines, trenchless construction managers must evaluate the use of temporary protective structures to retain the walls of the trench to prevent collapse.

Careful consideration must also be given to how the weight and vibration caused by operating equipment can affect excavated areas and nearby structures.

The recent COVID-19 worldwide outbreak has also highlighted the need for additional safety considerations in the workplace, namely the preparation of infectious disease preparedness and emergency response plans.

These plans are especially crucial for the trenchless industry since construction is deemed an "essential" service by several U.S. Jurisdictions.

Infectious disease preparedness and emergency response plans should consider and address the infection risks associated with various job sites and work activities.

Such considerations may include:

  • Where and how workers may be susceptible to contracting an infectious disease, including:

    • Interactions with coworkers, clients, and the general public
    • Travel history to locations with widespread and sustained disease transmission

  • Non-occupational risk factors at home and in community settings.

Some of the measures that companies can take to limit the exposure of their workers to infectious diseases include:

  • Enforcing social distancing among workers and clients.

  • Minimizing non-essential travel by utilizing video and teleconferencing to conduct meetings.

  • Staggering work shifts.

  • Minimizing human resources when conducting essential operations.

  • Utilizing remote trenchless technologies for pipeline assessments, such as CCTV cameras and drones equipped with thermographic imaging and leak detection technology.

Develop a Contingency Plan

According to Murphy’s Law, “Anything that can go wrong, will go wrong.” This saying is especially true in the high-risk construction industry. And when things do go wrong, they usually result in significant schedule and budget overruns.

Contingency plans can be considered to be a “Plan B.” In other words, it is a backup plan in the event that the trenchless installation or rehabilitation procedure does not progress as per the project plan.

It is, therefore, worthwhile to prepare a contingency plan should any identified risks materialize. These plans are usually developed during the early stages of project initiation so that all mitigation measures can be determined in advance.

It should be noted, however, that contingency plans can only be created for known or identified risk, and not unknown risks.

Conclusion

Like any other construction project, trenchless projects require early and meticulous planning. Some of the major advantages of planning include optimization of construction resources, on-time and on-budget project delivery, and minimized health and safety risks to construction personnel.

While the planning process may take additional time at the initial stage of the project, it can help maximize the probability of project success while minimizing the many risks associated with trenchless construction.