For decades, High Rise construction projects in Canada have brought with them a unique set of challenges related to dewatering. Now for the first time, there are new dewatering options available from WJ Groundwater Canada for Developers and GC’s to consider.
Firstly, now that many High Rise projects require extended parking levels 5 or 6 floors down many Developers realize that “traditional” rental based dewatering systems simply cannot achieve the draw down required.
Secondly, now that WJ Groundwater Canada offers Fixed Cost contract options on High Rise projects it is now obvious that dewatering contracts that do not protect the Owner and the Builder from under configured dewatering system proposals are obsolete.
Based on our experience with over 2500 dewatering projects worldwide since 1982 and our specialization in dewatering the most challenging deep excavation, tunnel and LRT mega projects over the years, our engineers have developed higher performance drilling equipment, pumping processes, well point systems, eductors and dewatering design services that offer significant and measurable increases in performance to dewater High Rise projects.
In addition, WJ’s proprietary 24 hour pump tests can be leveraged by our clients and their advisors to better understand the hydrological profile of any site and precisely size the dewatering system needed to achieve draw down goals. When combined with our in-depth understanding of local geology, our superior dewatering system performance, and our probono engineering services, these advantages combine to make WJ the perfect dewatering partner for Developers and GC’s in the High Rise business in Canada. For example, leveraging WJ expertise can help our High Rise clients avoid spending millions in temporary bath tubbing costs or more expensive hydro-static caisson wall systems.
WJ’s 360 degree, water rotary flush drilling makes all the difference
Outside of WJ, the dewatering industry mainly uses auger based drilling rigs that were designed decades ago primarily to drill farm wells. For urban High Rise projects they take up a lot of space on site and are limited to 90 degree drilling. More importantly with this old fashion “dirty” style of drilling smears clay on the sides of the holes bored to install the wells – which ends up waterproofing them and limiting connectivity of the eductor wells installed. Which greatly reduces their effectiveness.
In contrast, WJ uses much smaller 360 degree drilling rigs with water rotary flush technology which “pressure washes” the hole prior to the installation of our Extended Screen Eductors. This proprietary combination of WJ’s state of the art 360 degree drilling rigs and well technology produces 3 distinct advantages that represent significant improvements in performance for WJ dewatering systems designed for more challenging High Rise projects – as well as measurable dollar savings that increase profit for our clients:
- Major Savings Over Traditional Perimeter Eductor Based Systems in High Rise Projects. WJ’s unique 360 degree drilling methods and well designs give WJ the flexibility to install our dewatering systems through lagging or shoring walls using a number of options including inclined well points, inclined eductors, as well as from the surface or bottom of the excavation. This flexibility is unique to WJ and this advanced technology can reduce the cost of dewatering many High Rise projects as much as 35%+ when compared to “traditional” 2” perimeter educator systems (see Inclined Well Point and Eductor through Lagging illustrations below).
- TSS Free Water.In addition, the combination of WJ’s water flush drilling methods and WJ’s proprietary educator and well point extended screening technology, results in TSS free water exiting the WJ Systems – and completely eliminates the need, space and cost of the sedimentation tank systems required for “traditional” eductor dewatering systems.
- 300%+ Increase in WJ Eductor Dewatering Performance. WJ’s proprietary extended screen design for our 4” educator wells enables 300% to 400% of the flow compared to a “traditional” 2” eductor system. (See blue extended eductor screen example on left in WJ vs Competitor Eductor System illustration).
Find out more
Get in touch if if you’d like to find out more about our solutions for High Rise dewatering or our fixed cost dewatering.