Reducing Schedule & Financial Risk in all Seasons
Getting out of the ground is one of the major sources of cost and schedule risk on your construction and/or development projects. In certain cases, the soils on your project are unsatisfactory for the support of traditional footings and require a significant level of planning prior to constructing your foundation system. Soil conditions across your site are typically variable by nature, and preparing your site for construction often requires that you dig into the unknown, exposing your project to unexpected challenges and delays.
Soil conditions are not the only source of cost and schedule risk on your projects. At certain times of the year, getting out of the ground early can mean battling challenging conditions and inclement weather. Soils that are readily handled or compacted during the summer months can prove difficult to handle during the spring, fall and winter. The workability of soil will depend on many environmental factors including the in situ moisture content. Working in saturated soils conditions requires more time to handle and place material. These soils can also create concerns over unstable conditions at or near the bottom of footing creating potential safety issues and extra excavation volumes.
There is a reason the summer months are referred to as the “construction season”. Although, sweltering heat, humidity and heavy rain storms can also throw a temporary wrench into your outdoor construction activities, for the most part, summer construction is relatively predictable and dry with minimal environmental impacts on production rates and schedules.
This is not the case, however, when summer transitions through fall and into winter at which time your options for managing challenging soil conditions become increasingly restricted. Freezing temperatures make excavating and placing engineered fill nearly impossible and adds substantial effort to pouring and curing concrete for deep foundation systems. The availability of imported materials can also become challenging in many areas of Ontario. In northern communities, it can become especially difficult to deliver material to your site as trucks have often been converted to snow plows and quarries and pits often shut down. Dumping or receiving sites for fill are also often shut down during winter months.
Spring construction brings its own challenges, such as road restrictions on trucking soil/aggregates to and from construction sites (half-load season). Wet weather, soft/soggy ground conditions and higher groundwater levels require careful consideration and extra effort.
So what can you do to keep your project on track without increasing your cost and risk?
Schedule delays due to poor soil conditions can be avoided through proper project planning. Working with the project team early in the planning stages can help you avoid these delays through better understanding of your construction challenges. Once these challenges are identified and understood, you will be enabled to develop strategies to overcome the potential pitfalls and setbacks.
If your schedule demands are aggressive, you may need to work in inclement weather. Getting an early start on your construction will improve your schedule and create a buffer against unforeseen delays. If you plan to take advantage of opportunities to work in all seasons, it is important to carefully select your foundation support solution and to work closely with your project team to manage your soil related risk.
Many of our clients are cautious about over-excavation and the replacement of poor soils, especially during the late fall to early spring months when all the standard risks of dig-replace (uncertainty in soil volumes, risk of encountering contaminants, etc.) are coupled with the risks associated with poor and cold weather.
If you are looking for a solution that allows you to stick with a slab on grade/spread footing structure in poor soil conditions, what other options do you have other than massive overexcavation and replacement (engineered fill)?
As an alternative to over-excavation and replacement, Soil Reinforcement Solutions can get the heavy lifting done in winter so that you can get out of the ground come spring time. These systems allow for the use of standard spread footings and slab on grade foundation elements, and can provide double to triple the bearing capacity offered by engineered fill. Foundation permits are not required to install soil reinforcement systems allowing you to solve your foundation challenges in the early stages of the design process, shrinking the project schedule.
For more information on Soil Reinforcement and what it can do for your site, and what it can do for your site, click here.