Services - Rock Boring | L.J. Keefe Co.

Here at L.J. Keefe Co. our industry partners are of high importance. If you are interested in working with us, please reach out.
Contact us today.

CONTACT US

847.577.7715

ljkeefeco@ljkeefeco.com

Corporate Office
704 W. Central Road
Mount Prospect, IL 60056

Description

A 2-pass method to install steel casing, which employs (1) the installation of a hollow stem pilot tube with a guidance system, and (2) a following steel casing which is jacked-in-place by an auger boring machine while the soils are transported back to the jacking shaft by auger conveyance within the casing. If adverse soil conditions are encountered, the following steel casing can be rammed in place by a pipe ramming tool.

The guided pilot tube, the first pass, is installed by a hydraulically powered Guided Boring Machine that advances the pilot tubes while displacing the surrounding soil. Line and grade of the pilot tube's advance is continuously monitored by a theodolite optical guidance system. Steering of the GBM to maintain horizontal and vertical alignment is accomplished by the operator, who is viewing the advance of the pilot tube on the guidance system's monitoring screen and adjusting the pilot tube's heading for an accurate arrival in the receiving pit.

The casing adapter and the first length of casing, the 2nd pass, are mechanically connected to the string of pilot tubes. As each length of casing is welded together and auger bored/rammed in place, the pilot tubes are being retrieved at the receiving pit.

Application

The GBM is best suited for line and grade critical crossings over long distances. Guided Boring equipment can be utilized as a stand-alone system or in conjunction with Auger Boring and Pipe Ramming Equipment.

Casing/Pipe Material

Steel Casing Pipe

Diameter- 5/8" O.D. to 60" O.D.

Also utilized for the direct installation of small diameter Vitrified Clay Pipe (VCP) and No-Bell RCP.

Drive Lengths

Ranging from 25 LF up to 500 LF, depending on specified pipe material and anticipated ground conditions.

Soils

The steering head, which is attached to the lead pilot tube, is able to thrust through most soils (i.e., clay, sand, or small gravel).

Description

The steel casing pipe is machine bored (augured) and jacked-in-place simultaneously, so that there is no ‘open excavation’ in front of the casing. The soils are transported back to the work shaft by auger conveyance within the casing.

A cutting head suitable for the ground condition is attached to the lead auger. The cutting head is positioned immediately outside the casing in stable soils, permitting wing cutters to mine the face of the excavation heading one inch (1”) larger than the casing, thereby reducing the friction on the outside wall of the casing. In the event that unstable soils are encountered, the cutting head is retracted inside the casing. The cutting head, with full-size augers behind it, prevents loose soils from surcharging into the casing.

Grade of the steel casing is continuously monitored by water level and adjusted through the use of a steering head connected to the lead piece of casing. Line is checked at regular intervals by conventional surveying instruments, and manual adjustments can be made as necessary.

Application

Auger boring is a common, two-pass method for installing steel casing as a liner to accommodate a new underground utility (carrier) pipe. The casing diameter can be sized to accommodate any type of service pipe specified by the project's requirements.

Casing/Pipe Material

Steel Casing

Diameter from 12” O.D. to 84” O.D.

Limited to installing smooth-wall steel pipe due to the size.

Drive Lengths

Ranging from 25 LF up to 600 LF.

Soils

Standard dirt cutterheads are used for boring through clay and sand soils. The cutterheads can also be equipped with carbide tipped ‘bullet’ teeth for boring through full-face, soft rock and shale.

Description

The steel casing pipe is machine bored (augured) and jacked-in-place simultaneously, so that there is no 'open excavation' in front of the casing. The soils by auger conveyance within the casing.

A cutting head suitable for the anticipate ground condition is welded to the lead casing. Keefe would typically utilize a Robbins Small Boring Unit (Model SBU-A) with either the Rock Disc or Mixed Ground cutterhead attachment. For larger diameter casings or longer drive lengths, Keefe would rely on the Robbins Motorized Small Boring Unit (Model SBU-M) with either the Rock Disc or Mixed Ground cutterhead attachment.

Grade of the steel casing is continuously monitored by water level and adjusted through the use of a steering head fabricated to the lead piece of casing. Line is checked at regular intervals by conventional surveying instruments and manual adjustments can be made as necessary.

Application

Rock Boring is similar to auger boring in that Rock Boring utilizes a standard auger boring machine and augers for spoil removal. The difference is in the cutterhead attachment. Standard auger boring cutter heads are not equipped to cut through rock greater than 3,000 psi. Rock Disc cutter heads and Mixed Ground cutter heads manufactured by The Robbins Company provide Keefe with the capability to tackle the most challenging rock bores.

Casing/Pipe Material

Steel Casing Pipe

Diameter from 24" O.D. to 72" O.D.

Rock Boring is limited to smooth inside and outside wall steel pipe.

Drive Lengths

Ranging from 25 LF up to 500 LF +

Soils

Rock Disc cutterheads are typically used for boring through hard, full-face rock (4,000 - 25,000 PSI). In the event that mixed ground containing cobbles and boulders is anticipated, an alternative, mixed ground cutter head equipped with a combination of disc cutters, carbide insert cutters, and carbide cutter bits can be installed on the same housing assembly.

Description

The steel casing pipe is rammed in place using a pneumatic (air-powered) ramming tool. The size of the ramming tool is determined based on the required casing diameter and the anticipated ground conditions. The tool is attached to the back end of the casing by adapter collets or a soil cone/port.

The leading edge of the casing pipe is reinforced through fabrication of multiple, heavy-duty drive shoes to prevent the head from distorting or collapsing during the ramming process.

Grade of the steel casing is continuously monitored by water level, and the Line is checked at regular intervals by conventional surveying instruments. Note: Conventional steering equipment can not withstand the force of the ramming tool. In the event that the line and grade are critical over a long distance, it is recommended that the Pipe Ramming method be used in conjunction with the Guided Boring Method.

The soils within the casing pipe are removed by conventional auger boring equipment. In the event that ramming pressures become excessive during the casing installation, the soils can be removed by augering to a certain point, without affecting the heading of the casing pipe.

Application

Unlike the auger boring method, the Pipe Ramming method does  not remove the soils simultaneously with the advancement of the casing. The Pipe Ramming method utilizes a pneumatic hammer attached to the end of the casing and each section of casing is 'rammed' in place. Depending on the ground conditions, the soil inside the casing pipe can be removed by augering either during or after the installation of the entire length of casing. The ability to leave the soil inside the casing creates a plug which prevents soils from surging into the casing heading, in turn minimizing the risk of ground loss and settlement.

Casing/Pipe Material

Steel Casing Pipe

Diameter from 12" O.D. to 84" O.D.

Limited to smooth inside and outside wall made of steel pipe.

Drive Lengths

Typically ranging from 25 LF up to 200 LF. In the event that longer drives are required, the Pipe Ramming Method can be used in conjunction with the GBM to reach lengths up to 500 LF.

Soils

The Pipe Ramming method is suitable for any soils except rock. However, this method is most typically utilized to overcome the risks posed by free flowing soils such as sand, gravel, cobbles, or when high ground water levels are present.

Description

A Hand Mining shield is fabricated at the leading edge of the steel casing or bolted to the leading edge of reinforced concrete pipe/box.

The tunnel is mined and jacked-in-place simultaneously as the heading is excavated under the protection of the mining shield, so that there is no 'open excavation'. The excavated soils are transported by a haul train to the working shaft and hoisted to the surface grade for disposal off-site.

The line and Grade of the tunnel are checked at regular intervals by conventional surveying instruments, and manual adjustments can be made as necessary by Keefe's experienced mining personnel.

Application

Hand Mining is a method for installing a number of different pipe materials such as steel casing, reinforced concrete pipe, and reinforced concrete box segments. Hand Mining is a labor intensive process and is typically utilized in ground conditions not conducive to auger boring/tunneling and for shorter runs of large diameter concrete pipe/box segments. Hand Mining can also be employed in conjunction with other trenchless construction methods in the event that occasional obstructions and/or boulders are encountered within the tunnel alignment.

Casing/Pipe Material

Steel Casing Pipe

Diameter from 36"+ O.D./I.D.

Reinforced Concrete Pipe

Diameter from 36"+ O.D./I.D.

Reinforced Concrete Box Segments

Diameter 36"+ I.D.

Drive Lengths

Distance will vary based on pipe material and ground conditions.

Soils

Hand mining is typically utilized in the following ground conditions: clays, sand & gravel, cobble, and 'soft' rock. Hand mining is also employed for removal of large man-made or natural obstructions in otherwise suitable ground conditions.

Application

The primary intent of an underpass is to eliminate at-grade pedestrian congestion for vehicles and other motor traffic, thereby improving safety at railroad crossings and major intersections. The tunneling method allows the steel casing to be installed without taking mainline track or major roadways out of service.

Casing/Pipe Material

Circular Tunnel

Steel Casing - typical diameter of 10' to 14'. Reinforced Concrete Pipe (RCP) - typical diameter of 12' I.D. / 14' O.D.

Box Tunnels

Precast Concrete Box Segments (PCBS) – typical square dimension of 10' I.D. / 12' O.D.

Circular Tunnels

Box Tunnels

Description

The RCP/steel casing pipe fits into a receiving band at the back of the tunnel boring machine (TBM) and the TBM together with the following lengths of pipe are thrust (pushed) forward by a hydraulic jacking frame, located in the drive or working shaft, as the TBM excavates the soils. The excavated soils are transported by a haul train to the working shaft and hoisted to the surface grade for disposal off-site.

Keefe will determine which cutter head configuration should be used for excavating the tunnel based on information from soil boring logs and confirmed by actual soils observed during excavation of the work shaft.

Line and grade of the tunnel's advance shall be continuously monitored by a laser guidance system, which is checked by conventional surveying instruments. Steering of the TBM to maintain horizontal and vertical alignment is accomplished by the operator who is working in the TBM. The TBM's two piece construction permits it to articulate 360 degrees.

The RCP/steel casing lengths will be placed behind the TBM, and jacked-in-place. A plywood cushion is placed in each joint of the Reinforced Concrete Pipe to evenly distribute the jacking load across the entire bell/spigot. Steel casing lengths are joined by welding.

If necessary, a bentonite lubricant will be pumped through the national pipe thread (NPT) fittings, cast/welded in the wall of the pipe to reduce soil friction on the outside wall of the pipe. If required, upon completion of the tunnel drive, the annular space between the outside wall of the pipe and the tunnel excavation shall be contact-grouted.

Application

Conventional Tunneling/Pipe Jacking is a one-pass method for installing reinforced concrete pipe (RCP) to typically serve as a storm sewer. Tunneling can also serve as a two-pass method for the installation of large-diameter steel casing to facilitate a carrier pipe over long distances that would exceed the typical limits of the Auger Boring method.

Casing/Pipe Material

Reinforced Concrete Pipe

Diameter range – 42" I.D. to 12' I.D.

Steel Casing Pipe

Diameter range - 48" O.D. to 14' O.D.

Drive Lengths

Range from 25 LF up to 800 LF.

Soils

The tunnel boring machine has 4 cutter head configurations:

Dirt cutter bar for tunneling through clay and sandy clay soils.
Carbide-tipped, 'bullet' teeth cutter bar for tunneling through harder clays or soft rock/shale.
Sand shelves for tunneling in dry/dewatered sand soils.
Closed Face Attachment for tunneling through varying and unstable ground conditions.

Experience and Knowledge

Description

The guided pilot tube, the 1st pass, is installed by a hydraulically powered Guided Boring Machine that advances the pilot tubes while displacing the surrounding soil. Line and grade of the pilot tube's advance is continuously monitored by a theodolite optical guidance system. Steering of the GBM to maintain horizontal and vertical alignment is accomplished by the operator, who is viewing the advance of the pilot tube on the guidance system's monitoring screen and adjusting the pilot tube's heading for an accurate arrival in the receiving pit.

Application

Soils

The steering head, which is attached to the lead pilot tube, is able to thrust through most soils (i.e., clay, sand, or small gravel).

Casing/Pipe Material

Steel Casing Pipe

Diameter- 5/8" O.D. to 60" O.D.

Also utilized for the direct installation of small diameter Vitrified Clay Pipe (VCP) and No-Bell RCP.

Drive Lengths

Ranging from 25 LF up to 500 LF, depending on specified pipe material and anticipated ground conditions.

Description

Application

Soils

Casing/Pipe Material

Steel Casing

Diameter from 12” O.D. to 84” O.D.

Limited to installing smooth-wall steel pipe due to the size.

Drive Lengths

Ranging from 25 LF up to 600 LF.

Description

For larger diameter casings or longer drive lengths, Keefe would rely on the Robbins Motorized Small Boring Unit (Model SBU-M) with either the Rock Disc or Mixed Ground cutterhead attachment. Grade of the steel casing is continuously monitored by water level and adjusted through the use of a steering head fabricated to the lead piece of casing. Line is checked at regular intervals by conventional surveying instruments and manual adjustments can be made as necessary.

Application

Rock Boring is similar to auger boring in that Rock Boring utilizes a standard auger boring machine and augers for spoil removal. The difference is in the cutterhead attachment. Standard auger boring cutter heads are not equipped to cut through rock greater than 3,000 psi. Rock Disc cutter heads and Mixed Ground cutter heads provide Keefe with the capability to tackle the most challenging rock bores.

Soils

Casing/Pipe Material

Steel Casing Pipe

Diameter from 24" O.D. to 72" O.D.

Rock Boring is limited to smooth inside and outside wall steel pipe.

Drive Lengths

Ranging from 25 LF up to 500 LF.

Description

Conventional steering equipment can not withstand the force of the ramming tool. In the event that the line and grade are critical over a long distance, it is recommended that the Pipe Ramming method be used in conjunction with the Guided Boring Method. The soils within the casing pipe are removed by conventional auger boring equipment. In the event that ramming pressures become excessive during the casing installation, the soils can be removed by augering to a certain point, without affecting the heading of the casing pipe.

Application

Depending on the ground conditions, the soil inside the casing pipe can be removed by augering either during or after the installation of the entire length of casing. The ability to leave the soil inside the casing creates a plug which prevents soils from surging into the casing heading, in turn minimizing the risk of ground loss and settlement.

Soils

The Pipe Ramming method is suitable for any soils except rock.

However, this method is most typically utilized to overcome the risks posed by free flowing soils such as sand, gravel, cobbles, or when high ground water levels are present.

Casing/Pipe Material

Steel Casing Pipe

Diameter from 12" O.D. to 84" O.D.

Limited to smooth inside and outside wall made of steel pipe.

Drive Lengths

Typically ranging from 25 LF up to 200 LF. In the event that longer drives are required, the Pipe Ramming Method can be used in conjunction with the GBM to reach lengths up to 500 LF.

Description

A Hand Mining shield is fabricated at the leading edge of the steel casing or bolted to the leading edge of reinforced concrete pipe/box. The tunnel is mined and jacked-in-place simultaneously as the heading is excavated under the protection of the mining shield, so that there is no 'open excavation'. The excavated soils are transported by a haul train to the working shaft and hoisted to the surface grade for disposal off-site. The line and Grade of the tunnel are checked at regular intervals by conventional surveying instruments, and manual adjustments can be made as necessary by Keefe's experienced mining personnel.

Application

Hand Mining is a method for installing a number of different pipe materials such as steel casing, reinforced concrete pipe, and reinforced concrete box segments.

Hand Mining is a labor intensive process and is typically utilized in ground conditions not conducive to auger boring/tunneling and for shorter runs of large diameter concrete pipe/box segments. Hand Mining can also be employed in conjunction with other trenchless construction methods in the event that occasional obstructions and/or boulders are encountered within the tunnel alignment.

Soils

Hand mining is typically utilized in the following ground conditions: clays, sand & gravel, cobble, and 'soft' rock.

Hand mining is also employed for removal of large man-made or natural obstructions in otherwise suitable ground conditions.

Casing/Pipe Material

Steel Casing Pipe

Diameter from 36"+ O.D./I.D.

Reinforced Concrete Pipe

Diameter from 36"+ O.D./I.D.

Reinforced Concrete Box Segments

Diameter 36"+ I.D.

Drive Lengths

Distance will vary based on pipe material and ground conditions.

Application

Casing/Pipe Material

Circular Tunnels

Steel Casing - typical diameter of 10' to 14'.

 Reinforced Concrete Pipe (RCP) - typical diameter of 12' I.D. / 14' O.D.

Box Tunnels 

Precast Concrete Box Segments (PCBS) – typical square dimension of 10' I.D. / 12' O.D.

Circular Tunnels

Box Tunnels

Description

Keefe will determine which cutter head configuration should be used for excavating the tunnel based on information from soil boring logs and confirmed by actual soils observed during excavation of the work shaft. Line and grade of the tunnel's advance shall be continuously monitored by a laser guidance system, which is checked by conventional surveying instruments. Steering of the TBM to maintain horizontal and vertical alignment is accomplished by the operator who is working in the TBM. The TBM's two piece construction permits it to articulate 360 degrees. The RCP/steel casing lengths will be placed behind the TBM, and jacked-in-place. A plywood cushion is placed in each joint of the Reinforced Concrete Pipe to evenly distribute the jacking load across the entire bell/spigot. Steel casing lengths are joined by welding.

If necessary, a bentonite lubricant will be pumped through the national pipe thread (NPT) fittings, cast/welded in the wall of the pipe to reduce soil friction on the outside wall of the pipe. If required, upon completion of the tunnel drive, the annular space between the outside wall of the pipe and the tunnel excavation shall be contact-grouted.

Application

Soils

The tunnel boring machine has multiple cutter head configurations:

Dirt cutter bar for tunneling through clay and sandy clay soils.
Carbide-tipped, 'bullet' teeth cutter bar for tunneling through harder clays or soft rock/shale.
Closed Face Attachment for tunneling through varying and unstable ground conditions.

Casing/Pipe Material

Reinforced Concrete Pipe

Diameter range – 42" I.D. to 144" I.D.

Steel Casing Pipe

Diameter range - 48" O.D. to 168" O.D.

Drive Lengths

Range from 25 LF up to 800 LF.

L.J. Keefe Company offers a comprehensive range of specialized services
tailored to meet the demands of tunnel construction and engineering
projects. Our seasoned professionals are equipped with knowledge,
experience, and cutting-edge technology to ensure successful execution of
tunneling endeavors.

Here at L.J. Keefe Co. our industry partners are of high importance.

If you are interested in working with us, please reach out.

Contact us today.

CONTACT US

847.577.7715

info@ljkeefeco.com

Corporate Office
704 W. Central Road
Mount Prospect, IL 60056