water cut-off in hard rock tunnel

Innovative Water Cut Off Solution for a Hard Rock Tunnel

Location: Sudbury, ON
Sector: Tunnels
Category: Cement Grouting

Description

A large tunneling contractor found itself in a difficult situation with a large flowing water leak in a new rock tunnel 20 metres underground. During tunnel construction, localized areas of bad ground conditions were encountered, characterized by heavily fractured rock.

Conventional cement grouting was used by the tunneling contractor to control water inflows in some of these areas. An evaluation of the particular site conditions by the Multiurethanes crew determined that debris and broken ground made it impossible to accurately identify the primary water-bearing fracture as experienced by the tunneling crew when initial injections were washed out by the large water inflow.

An innovative solution involving chemical grouting through single grout hole injection while isolating and identifying nearby localized leaks was successfully implemented. The specialized nature of the water cut-off grouting work required a combination of materials, equipment and experience, including Multiurethanes Universal Resin, a pneumatic chemical pump and skilled grouting techniques performed by our experienced grouting specialists.

The secret to this successful water cut-off project was the application of appropriate grouting techniques, equipment and materials for the existing site conditions.

cement grouting to stabilize retaining toll

Emergency Cement Grouting Operation to Stabilize a Retaining Wall

Location: Toronto, ON
Sector: Infrastructure
Category: Cement Grouting

Description

The City of Toronto required Multiurethanes‘ technical expertise for an emergency cement grouting project to stabilize an undermined retaining wall over a 50 m length.

One of the biggest challenges was accessing the work area through heavy bush over a small muddy path. Once there, our grouting technicians drilled steel grout pipes into the bottom of the retaining wall. The grouting equipment was transported to the site by using a loader and consisted of a portable grout mixing and pumping unit with ancillary water supply.

This emergency project was completed within four days and required 500 bags of high-performance non-shrink grout. A solid foundation was created to permanently stabilize the retaining wall and adjacent embankment.

 

Training on grouting equipment at mine site

Grouting Equipment On-site Training

Location: Chihuahua, MEXICO
Sector: Mines
Category: Cement Grouting

Description

An international mining company, with operations in Canada, Europe and Latin-America, contacted us to provide specialized training on grouting equipment.

One of our technicians traveled to a mine site, located in northern Mexico, to conduct training in Spanish to their personnel on the maintenance and use of their hydraulic grout plant.

During the training session, our specialist, as well as providing detailed theoretical information, also presented practical instructions on the proper maintenance, operation and safety precautions of the plant.

Additionally, guidelines for the safe operation on high-pressure grouting applications were an important part of the training session

Soil Stabilization for Utility Contractor

Soil Stabilization Program for Utility Contractor

Location: Toronto, ON
Sector: Utilities
Category: Cement Grouting

Description

An underground utility contractor encountered loose fill after initial exposure of an open trench excavation. A Hydrovac was used to vacuum excavate the trench daylighting locates when fill began to collapse into the trench from beneath the sidewalk and road.

From the perimeter of the trench, parallel holes were drilled at 3-foot intervals, at alternating depths of 10 feet and 5 feet. 1/2 inch brake lines were driven into the subgrade using a hammer drill, to the correct depth. 60 litres of cement grout were injected into the drilled holes through the brake lines, permeating into the loose fill, binding with the fill to form a cement stabilized base.

Cement grout injection using Multiurethanes Microfine Cement and Superplasticizer, 1/2 inch Brake Lines, four chemical pumps, and a CG Mixer 22E were used to stabilize the backfill along the perimeter of the open trench. The stabilization program eliminated the potential for collapse of the open trench, allowing for the utility contractor to continue the excavation operation without incident.

Grouting Tunnel Cross passage

Cement Grouting to Fill Voids in Tunnel Cross Passage

Location: Toronto, ON
Sector: Infrastructure
Category: Cement Grouting

Description

A public transportation agency encountered water infiltration into the subway system, due to voids behind the cross passage section of the tunnel.

Working within the cross passage segment of the tunnel, 15 investigative holes were drilled to identify the location of the voids which contained water. Mechanical packers with ball valve assembly were then installed into the drilled holes where the presence of water inflow was observed. Cement grout was continuously injected into the drilled holes via the mechanical packers until grout was detected resurfacing from an adjacent open valve. The resurfacing of grout indicated that the cavity had been filled, as the water had been displaced away from the cross passage section.

Cement grout injection using Multiurethanes Microfine Cement, mechanical packers and a chemical grout pump were used to fill the voids behind the cross passage section. The method eliminated the infiltration of water into the tunnel and allowed utility contractors to work safely within the cross passage.

cement grouting for pipe decommission

Void Filling in Pipe Decommission

Location: North York, ON
Sector: Utilities
Category: Cement Grouting

Description

Following a pipe’s abandonment, a utility contractor discovered a washed out area above the pipe with the potential to collapse in the future and create voids that could lead to a sinkhole. Structural void filling and permanent abandonment works were required.

A bulkhead was designed and installed to successfully fill the pipe and the void using a heavy cement slurry.

Void Filling under Factory Facility

Location: Guelph, ON
Sector: Industrial
Category: Cement Grouting

Description

Multiurethanes’ technical crew supported a cement grouting program required to fill underground voids encountered under a factory facility.

A mix of non-shrink grout and water was pumped into 1 1/2’’ holes drilled into the void until the grout started flowing from the holes. This evidence and the use of a pressure gauge determined that the voids were successfully filled.

Epoxy injection on canal wall

Epoxy Injection in Canal Wall

Location: Port Colborne, ON
Sector: Industrial
Category: Chemical Grouting, Cement Grouting

Description

A restoration contractor refurbishing the canal and lock gates found a 3/8” x 40’ joint within the canal wall which needed to be sealed from infiltration of water.

Work commenced from within the trench and above the wall, where 3/8” holes were drilled into the canal wall. 80 holes were drilled in a staggered pattern atop the wall, holes were drilled every 12” straight down into the joint at a depth of 18”, and holes were drilled every 6” at a 60-degree angle to intersect the joint towards the face of the wall at a depth of 21”. 3/8” plastic packers were placed into the drilled holes and the 40’ joint was then pargeted with hydraulic cement to ensure the limited loss of injected material.

The injection process took place in 2 stages; the first stage of the injection began with the injection of epoxy into the holes which were spaced every 6” and drilled at a 60-degree angle towards the face of the canal wall, to ensure the limited loss of injected material. The epoxy cured sealing the joint towards the canal, and the hydraulic cement cured sealing the joint towards the trench, with the expectations of inclosing the epoxy for the second stage of injection. The second stage of injection then took place by injecting into the holes which were drilled every 12”, straight down into the joint at a depth of 18”. The joint was filled with epoxy, forming a rigid barrier, preventing the infiltration of water into the canal wall.

Chemical grout injection using epoxy resin (part A and B), 3/8” plastic packers, and a chemical grout pump were used to seal the joint in the canal wall. The application eliminated the possibility of future water infiltration into the canal wall.

Equipment Customization for Cement Grouting

Equipment Customization for Cement Grouting

Location: Mount Pleasant, NY
Sector: Utilities
Category: Cement Grouting, Chemical Grouting

Description

A municipal water supply organization was constructing a large water treatment facility situated on the outskirts of New York City. Construction crews encountered a leaking bypass pipe at a depth of 400 feet below the surface between two adjacent deep water supply shafts.

Multiurethanes grouting specialists supported decommissioning operations undertaken by a deep dive contractor to fill the defective bypass pipe using cement grout.  In addition, they prepared customized electrical equipment for this underwater grouting project, including a diesel generator and an electrical control panel with variable frequency drives to operate colloidal mixer, agitator tanks, and progressive cavity pumps.