Building Manual for F P McCann `Smoothbore Shaft Linings with EPDM Gaskets (rev 04) (To be read in conjunction with the Segmental Shaft and Tunnel Safety Data Sheet) Segmental ring types provided by F P McCann: Segments in stock are front bolted. Back bolted segments are available to order: 1. Standard rings 2. Corbel rings 3. Recessed rings (standard, choker or cutter choker) * 4. Choker rings * 5. Combined cutter choker rings * made to order Cover Slab Circle joint Standard Ring Cross joint Corbel Ring Landing slab Cutter Choker Ring General All rings, with the exception of the cutter choker comprise of ordinary segments and two top segments. The top segments have one tapered cross joint in order that they can be installed with EPDM gasket. The cutter choker comprises all ordinary segments. All segments are supplied with a factory fitted EPDM gasket as the primary sealing system. Cross joint connections are made using a spear bolt passing through a pocket in one segment and a plastic socket in the adjacent segment. Circle joint connections are made using a T bolt passing through a hole in one segment and into a T box in the adjacent segment.
Segment Handling 1. Lifting All segments, with the exception of the cutter choker, are delivered vertical. Segments are lifted using F P McCann T fingers which locate into T box type sockets, cast into the segments. No other T finger should be used. There will be either two or four specified lifting positions depending on segment size, all of which must be used. The Safety Data Sheet provides the relevant information with regard to the lifting equipment required when using either static or moving crane. Refer to diagram below for minimum chain angles. Alternatively a spreader beam may be used. Crane hook Crane hook 80 80 To secure the T finger, lift the sliding safety catch and insert into the full depth of the T box and turn through 90. Pull back until the T head of the bolt engages into the two internal clips. Push the safety catch into the T box to prevent the assembly from becoming accidentally disengaged. The cutter choker is delivered horizontal and should be turned on site. The T boxes and fingers should not be used for turning. The units should be turned either with slings (supplied by others) or using the 2 no threaded sockets cast into the circle joint. The appropriate lifting loops should be used (supplied by others). 2. Storage / Stacking Segments for shafts are typically stacked vertically. When stacked in this manner the first row should be placed on two timber bearers on even and firm ground. Subsequent rows, placed on top, should be separated with two timber bearers. Further measures will need to be taken to ensure the stacks are stable. The maximum height the segments should be stacked is two unless otherwise instructed by the Site Engineer. Stabilizing bars First row
Shaft design The rings / segments are designed by F P McCann for handling and installation only. The overall shaft design should be undertaken by the Scheme Engineer. For advice contact F P McCann Technical Department. Building Sequence Three methods of installation are described in this document. The sequences of installation are indicative and the exact method of installation is the responsibility of the Contractor. Health and Safety measures that apply specifically to segments and their fittings are indicated, other measures that apply to the shaft construction e.g. temporary guard rails to the top of the shaft, are the responsibility of the Contractor. For all methods the bitumen packers are required and are supplied. These packers should be secured to one cross joint face of each segment. A building tool is available from F P McCann to lift, locate and turn the T bolts into the correct orientation. Long reach sockets are available from F P McCann for fixing of the cross and circle joint bolts.
Building Sequence Underpinning Method The installation should proceed as follows: - Excavate a circular hole, typically to accommodate one or two rings and the concrete collar. Build the rings to correct line and level to the surface see `Building sequence Chimney fashion. Locate reinforcing bars through the wall. Pour the concrete collar. Note: The reinforcing bars and collar should be of sufficient strength and size to be capable of anchoring the rings, thereby supporting the weight of subsequent rings before grouting. Excavate the depth of 1.5 rings. The excavation should extend approximately 50mm beyond the outside diameter of the rings. Excavated area
Offer up the first ordinary segment to the ring above using an underpinning frame with all T bolts hanging in the through holes. Place the segment approximately 300mm below its intended position, with the centre of the segment directly underneath a joint on the ring above. Supports should be placed on top of the segment to avoid trapped hands should the segment be lifted unexpectedly. Lift and locate the `T bolts into the segments above, turning each clockwise through 90 and pulling downwards to lock them in position. A slot is located at the end of the thread. The slot should be in the correct orientation in the locked position i.e. radial. Optional: Insert one number locking wedge into the each T box. T Box Insert wedge into T box T bolt Wedge Check that the slot on the threaded end of each bolt points towards the centre of the shaft. Evenly tighten the `T bolts. Repeat the sequence until the gasket is compressed taking care not to overtorque any bolt as this may result in stripping of the threads. * Typical torques required range between 100Nm and 150Nm. 200Nm should not be exceeded without discussion with FM Technical Department. The degree of gasket compression required is dependent on the water pressure to be resisted. It should be noted that the circle joint has a flatness tolerance therefore full closure of the joint cannot be expected. Contact FPM Technical Department for further assistance if required.
The relative position of the bolts and the gasket may result in some `birds mouthing. The use of timber shims or wedges at the intrados of the joint, which should be removed as the joint is closed, can correct this. Check the segment for plumb. The underpinning frame should remain in position until all T bolts are fully tightened. The T bolt is not intended or designed to perform as a safety device. Site assessments should be undertaken by the installer and provisions made to ensure the safety of persons installing segments. When building the next and subsequent ordinary segments, follow the sequence as described below: Lubricate the gaskets on the mating surfaces of the segment. Offer the unit up using an underpinning frame and engage the `T bolts and locking wedge as described previously. Lift the segments and tighten the `T bolts to close the circle joint sufficient to position spear bolts into sockets on cross joint. The cross joint bolts may now be located and tightened to achieve a cross joint width of approximately 5mm. Evenly tighten all bolts within the circle and cross joints to compress the gasket. *Typical torques required range between 100Nm and 150Nm. 200Nm (T bolt) and 150Nm (cross joint bolts) should not be exceeded without discussion with FPM Technical Department. The degree of gasket compression required is dependent on the water pressure to be resisted. It should be noted that the circle joint faces have a flatness tolerance therefore full closure of the joint cannot be expected. Contact FPM Technical Department for further assistance if required. When building the top segments follow the sequence as described below: Install the first top segment as described above with the wide side uppermost. Offer up the second top segment. It may be necessary to excavate the ground locally to an additional depth in order to insert the last unit. Tighten the bolts as described for the ordinary segments. Close the gap between the excavation and the rings and grout the shaft through the grout sockets / non return valves cast into the segments. Fit the grout plugs on completion. Important note no more than one ring should be erected before grouting.
Repeat the process for all subsequent rings. A base slab may then be cast under or within the bottom of the shaft. The installation of seals will be required to avoid tracking of water through vertical holes, segment joints and between the base slab and the rings. For advice contact F P McCann Technical Department. The details below are typical and do not apply to all shafts.
Fixings may be either single or double row depending on shaft diameter T Box EPDM gasket Fill void at caulking groove with Tunnelling Accessories `Aquaflex' sealant Through holes to be sealed using T Bolt and Tunnelling Accessories Hydrophilic `Puh' washer 40 O/d x 16 I/d x 4 thk. T Bolt Tunnelling Accessories Hydrophilic sealing strip ref S204 around circumference of shaft 50 min. Insitu concrete 50 min. One layer, of Tunnelling Accessories Hydrophilic sealing strip ref S204, per cross joint (trim bituminous packer to suit) Bolt pocket Insitu concrete Section through T bolts Section through Cross joint Insitu concrete base plug The rings may be caulked and pointed.
Building Sequence Caisson method The shaft may either be sunk using a F P McCann combined concrete cutter/choker ring or a steel cutting edge (supplied by others). The installation should proceed as follows: Excavate a circular hole, typically to accommodate one or two rings and the concrete collar. Build the cutter choker ring to correct line and level, using either a concrete cutter choker ring or steel cutting edge secured to either a concrete choker ring or concrete standard ring. Steel cutting edge. Short T bolts are available to secure the steel cutter to the concrete ring over. Lift, locate and tighten the short T bolts through the steel plate into the T boxes located on the underside of the first concrete ring. The first concrete ring may be a standard ring or choker ring.
Concrete cutter choker. Standard length T bolts are provided to secure the concrete cutter choker ring to the concrete ring over. Place all T bolts in the through holes of the concrete cutter choker ring (T section uppermost). Place supports on the top of each segment to avoid trapped hands as the segment over is lowered into position. Lift and locate the `T bolts into the segments above, turning each clockwise through 90 and pulling downwards to lock them in position. A slot is located at the end of the thread. The slot should be in the correct orientation in the locked position i.e. radial. The installation of seals to avoid tracking of water through the vertical holes and segment joints may be required at this stage. For advice contact F P McCann Technical Department (Refer to base sealing diagrams at the end of this section). Wrap sheets of polystyrene or other suitable material around the extrados of the ring(s) to provide an annulus between the collar and the rings, which can be filled with bentonite slurry if required. Note: The F P McCann choker increases the segment width by 50mm. Pour the concrete collar. Note: The collar should be of sufficient size and strength to be capable of supporting the hydraulic rams. Install the hydraulic rams. Lower the first ordinary segments to the ring below with the required `T bolts hanging downward in the through holes. For sizes up to and including 7.5 ID, only two T bolts are required which should
be placed in the inner through holes. Note: Other holes are provided for installation using the underpinning method. Place supports on the top of each segment to avoid trapped hands as the segment over is lowered into position Lower the segments onto supports with the segment centre directly above a joint on the ring below. Locate the `T bolts into the segments below, turning each clockwise through 90 and pulling upwards to lock them in position. A slot is located at the end of the thread. The slot should be in the correct orientation in the locked position i.e. radial. Optional: Insert one number locking wedge into each T box. Wedge T bolt Insert wedge fully into T box T Box The supports should then be removed; taking care to avoid trapped hands should the segment move unexpectedly. The segments can then be lowered into the correct position. Check that the slot on the threaded end of each bolt points towards the centre of the shaft. Evenly tighten the `T bolts. Repeat the sequence until the gasket is compressed taking care not to over-torque any bolt as this may result in stripping of the threads. * Typical torques required range between 100Nm and 150Nm. 200Nm (T bolt) should not be exceeded without discussion with FPM Technical Department. The degree of gasket compression required is dependent on the water pressure to be resisted. It should be noted that the circle joint has a flatness tolerance therefore full closure of the joint cannot be expected. Contact FPM Technical Department for further assistance if required.
The relative position of the bolts and the gasket may result in some `birds mouthing. The use of timber shims or wedges at the intrados of the joint, which should be removed as the joint is closed, can correct this. Check the segment for plumb. When building the next and subsequent ordinary segments, follow the sequence as described below: Lubricate the gaskets on the mating surfaces of the segment. Lower the unit supports onto the ring below, engaging the `T bolts as described previously. Remove the supports and lower the segments. Tighten the `T bolts sufficient to position spear bolts into sockets on cross joint. *Typical torques required range between 100Nm and 150Nm. 200Nm (T bolt) should not be exceeded without discussion with FPM Technical Department. The cross joint bolts may now be located and tightened to achieve a cross joint width of approximately 5mm *Typical torques required range between 100Nm and 150Nm. 150Nm (cross joint bolts) should not be exceeded without discussion with FPM Technical Department. Evenly tighten all bolts within the circle and cross joints to compress the gasket as previously described. When building the top segments follow the sequence as described below: Construct the first top segment as described above with the wide side downwards. Lower the second top segment. Tighten the bolts as previously Push the rings into the ground using the hydraulic rams or suitable kentledge spread evenly about the ring. Use bentonite slurry within the annulus around the shaft to assist sinking if required. Excavate the ground within the built rings. Care should be taken not over excavate to ensure that the shaft does not sink in an uncontrolled way. Push the rings to a depth to enable the next ring to be erected. Build the next ring as described above and the process repeated until the desired depth is achieved. Grout the shaft using the grout sockets / non return valves cast into the segments. Install the grout plugs on completion. A base slab may then be cast within the bottom of the shaft. The installation of seals will be required to avoid tracking of water through vertical holes, segment joints and between the base slab and the rings. For advice contact F P McCann Technical Department.
Concrete cutter choker base sealing details: The details below are typical and do not apply to all shafts.
T Box EPDM gasket T Bolt Smoothbore Cutter/Choker ring Tunnelling Accessories Hydrophilic `Puh' washer 40 O/d x 16 I/d x 4 thk. Fill void at caulking groove with Tunnelling Accessories `Aquaflex' sealant Tunnelling Accessories Hydrophilic sealing strip ref S204 around circumference of shaft 50 min. 50 min. Section through T bolt & Thru' hole Insitu concrete base plug Tunnelling Accessories Hydrophilic `Puh' washer 40 O/d x 16 I/d x 4 thk. Section through Cross joint One layer, of Tunnelling Accessories Hydrophilic sealing strip ref S204, per cross joint (trim bituminous packer to suit) Insitu concrete base Bolt pocket Steel cutting edge base sealing details: The details below are typical and do not apply to all shafts. McCann Standard Smoothbore ring Through holes to be sealed using epoxy mortar or other, prior to shaft construction, to prevent possible water paths. Bottom ring only T Box 150 long Tee Bolt Insitu concrete base plug Steel Cutter ring (Supplied by others) Section through Tee bolts Section through Thru' hole
EPDM gasket Fill void at caulking groove with Tunnelling Accessories `Aquaflex' sealant Tunnelling Accessories Hydrophilic sealing strip ref S204 around circumference of shaft 50 min. 50 min. One layer, of Tunnelling Accessories Hydrophilic sealing strip ref S204, per cross joint (trim bituminous packer to suit) Bolt pocket Section through Cross joint
Building Sequence Chimney fashion The installation should proceed as follows: Excavate the ground to the required depth for the shaft. Cast a base slab in the bottom of the excavation. The installation of seals to avoid tracking of water through the vertical holes and segment joints may be required at this stage. Refer to diagrams for base sealing for the underpinning method. These details are typical and do not apply to all shafts For advice contact F P McCann Technical Department Place the segments into position and bolt to adjacent segments until a complete ring is built. Lower the first ordinary segments to the ring below with the required `T bolts hanging downward in the through holes. For sizes up to and including 7.5 ID, only two T bolts are required which should be placed in the inner through holes. Note: Other holes are provided for installation using the underpinning method. Place supports on the top of each segment to avoid trapped hands as the segment over is lowered into position Lower the segments onto supports with the segment centre directly above a joint on the ring below. Locate the `T bolts into the segments below, turning each clockwise through 90 and pulling upwards to lock them in position. A slot is located at the end of the thread. The slot should be in the correct orientation in the locked position i.e. radial.
Optional: Insert one number locking wedge into each T box. Wedge T bolt Insert wedge fully into T box T Box The supports should then be removed; taking care to avoid trapped hands should the segment move unexpectedly. The segments can then be lowered into the correct position. Check that the slot on the threaded end of each bolt points towards the centre of the shaft. Evenly tighten the `T bolts. Repeat the sequence until the gasket is compressed taking care not to over-torque any bolt as this may result in stripping of the threads. *Typical torques required range between 100Nm and 150Nm. 200Nm (T bolt) should not be exceeded without discussion with FPM Technical Department. The degree of gasket compression required is dependent on the water pressure to be resisted. It should be noted that the circle joint has a flatness tolerance therefore full closure of the joint cannot be expected. Contact FPM Technical Department for further assistance if required. When building the next and subsequent ordinary segments, follow the sequence as described below: Lubricate the gaskets on the mating surfaces of the segment. Lower the unit supports onto the ring below, engaging the `T bolts as described previously. Remove the supports and lower the segments. Tighten the `T bolts sufficient to position spear bolts into sockets on cross joint. *Typical torques required range between 100Nm and 150Nm. 200Nm (T bolt) should not be exceeded without discussion with FPM Technical Department. The cross joint bolts may now be located and tightened to achieve a cross joint width of approximately 5mm *Typical torques required range between 100Nm and 150Nm. 150Nm (cross joint bolts) should not be exceeded without discussion with FPM Technical Department. Evenly tighten all bolts within the circle and cross joints to compress the gasket as previously described. When building the top segments follow the sequence as described below: Construct the first top segment as described above with the wide side downwards. Lower the second top segment. Tighten the bolts as previously Repeat the process for all subsequent rings. The void around the shaft may be back filled using a granular fill or concrete. This should be placed and compacted evenly around the shaft to avoid uneven loading.the Scheme Engineer should advise on the method that is suitable as it is dependent on ground conditions and use of shaft.
Important notes: 1 It is important that the circularity of the rings are maintained throughout the installation process as any deflection will most likely increase as the shaft is installed. The segment connections are designed to allow some ovality but if this is exceeded then cracking and subsequent failure of the concrete around the fittings could take place. 2 Should the shaft be pointed before the water pressure is allowed to act on the shaft then spalling of the concrete along the caulking groove could result due to load transfer through the pointing. *The recommended torques are based on clean sheradised bolts with no lubricant applied. The torque is very dependent on the friction in the system i.e. condition of the bolts / sockets on site, therefore these are for guidance only. Ancillary Items Available from F P McCann or recommended specialist supplier Shaft slabs Pre cast cover and landing slabs. Shaft fittings Tie rod type fittings to allow segments to be built `in-line. Short `T bolts - for fixing the steel cutter to the choker ring. Locking wedges for T boxes. Shaft specialist building equipment / materials A T bolt long reach socket - used when tightening the `T bolts. A spear bolt long reach socket used when tightening the spear bolts. T bolt building tools used for pulling the `T Bolt head into the internal clips in the `T box. T lifting fingers see segment handling. Underpinning frame (underpinning building method only) Grout socket adaptors used as an adaptor for grouting equipment. Grout socket lifting ball used for lifting horizontally in special circumstances Hydrophyllic washers used for sealing though holes. (Refer to base sealing details within installation sequence) Hydrophyllic strip used for sealing segment joints and as a circumferential base seal. Refer to base sealing details within installation sequence) Lubricant for gaskets