1. PURPOSE
1.1 This global engineering specification defines for the contractor the minimum safety requirements associated with the installation of piles.
2. scope of work
2.1 The contractor shall furnish all labor, tools, material, and equipment (other than that specifically called out on the contract drawings and specifications as being furnished by Air Products) necessary to safely install complete piling systems according to governmental regulations.
2.2 This specification is not complete unless used with 4WCE-600500 and 4WCE-600700, 4ACE-600700 or 4ACE-600702.
3. RELATED DOCUMENTS
3.1 Air Products Engineering Documents
4ACE-600700 Construction Safety – Air Products Program
4ACE-600702 Construction Safety – Contractor Program
4WCE-600500 Crane and Lifting Procedures
4WCE-600700 Construction Safety
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LEADS REQUIREMENTS
4.1 Before starting any site pile driving, the contractor shall have the pile driving equipment (such as pile hammer, leads structure, auger equipment, and hoisting cables) thoroughly inspected by the manufacturer or representative, such as a structural engineer, and the Air Products representative to establish the equipment’s readiness for service. If repairs are required, the repairs must be made by a certified welder, which is approved by the manufacturer of the leads. Any such weld repairs must be handled as described in paragraph 5.1. The contractor must perform a visual inspection of all pile driving equipment each morning before work begins; all findings and deficiencies must be documented immediately and a copy given to the Air Products representative. The leads must be set on the ground for any major repairs to equipment such as the leads, hammer, and sheaves.
4.2 The swivel assembly and pin that connects the crane boom to the leads must be inspected before the start of any driving activities. A visual inspection is required to check for cracks in the weld, base metal, or the heat-affected zone of the assembly. If a crack or deficiency is found, the contractor shall perform ultrasonic or x-ray examination to determine the structural integrity of the assembly.
4.3 Stop blocks shall be provided for the leads to prevent the hammer from being raised against the head block.
4.3.1 A blocking device capable of safely supporting the weight of the hammer shall be provided for placement in the leads under the hammer, at all times while employees are working under the hammer.
4.3.2 Guards shall be provided across the top of the headblock to prevent the cable from jumping out of the sheaves.
4.3.3 When the leads must be inclined or angled for the driving of batter piles, provisions shall be made to stabilize the leads.
4.4 The leads of the pile driver must have fixed ladders, and continuous fall protection must be provided for personnel climbing these ladders, according to governmental regulations. Personnel are prohibited from climbing the leads during the driving operation. The minimum requirements for fall protection on walkways from the outriggers to the leads or the crane shall be as follows:
4.4.1 All walkways shall be kept clear of material and debris.
4.4.2 All walkways shall be installed with approved handrails and toeplates.
4.4.3 On fixed leads, the outriggers to the leads shall be equipped with an expanded metal grating walkway. If this is not possible, use two 2-in x 6-in boards, cleated together to form a walkway. Regardless of walkway used, a temporary railing shall be installed.
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HAMMER REQUIREMENTS
5.1 If guide beams must be welded to the hammer casing, the following steps must be done before driving piles:
5.1.1 The contractor shall submit details of the attachment to Air Products for review. These details or sketches must be generated and approved by a qualified engineer or the manufacturer.
5.1.2 A certified structural welder, approved by the manufacturer, shall be employed to make the attachment weld(s).
5.1.3 Dye-penetrant examination of the welds shall be performed.
5.1.4 A wire rope shall be attached, sufficient in size and safety factor to support the weight of the beams, above the attached beams and to the hammer casing, so the beams cannot fall even if the welds should fail.
5.2 A daily inspection of the hammer attachment shall be made to identify any potential hazard(s).
5.3 All hose connections to pile driver hammers shall be securely attached with an adequate length of at least 6 mm (1/4 in) alloy steel chain or cable having a minimum of 1500 kg (3,250 lbs) working load limit. These safety devices prevent the line from whipping if any couplings become disconnected.
5.4 The pile hammer shall not be activated or moved while a worker is ascending or descending the ladder on the leads. If a worker must ascend the leads to position a pile (that is, thread rebar through the hammer of concrete piles), the operator must not operate the rig; a “hands off” mode must be observed. The operator must take the signals from the worker doing the positioning.
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CRANES
6.1 The contractor shall consult 4WCE-600500 for further details and requirements regarding cranes and proper rigging techniques.
6.2 The piling rig shall be moved only with hammer set low in the leads.
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PRE-FORMED PILES
7.1 Lifting or carrying of pile sections, planks, or timbers might present serious strain exposure to personnel and equipment. This potential hazard might also be magnified by muddy or slippery conditions. Adequate personnel or mechanical assistance (such as forklifts or cranes) shall be required.
7.2 When handling piling, special care needs to be taken to protect workers from being struck by falling pile or debris as follows:
7.2.1 Piles shall be handled one at a time.
7.2.2 Grab-lines shall be hooked at least 1 m (3 ft) from the end of the pile. On woodpiles, use alloy chains with hooks. When handling concrete or pipe piles, or when working in close quarters, a cable with a shackle should be used. A safety factor of 5:1 shall be used for all types of rigging being used.
7.2.3 Only one signal person shall direct the pile driver operator, preferably a foreman, someone designated by the foreman, or an experienced supervisor.
7.2.4 When dragging a pile, the hammer shall be set low in the leads.
7.3 Tag lines must be used to control unguided piling. Piling grab-lines shall be secured at all times to prevent swinging into someone.
7.4 If wooden creosote piling is being driven, proper protective clothing, for example, long-sleeve shirts, gloves, and eye and face protection must be worn to protect personnel against creosote exposure.
7.5 Stacking of piling shall be kept to a minimum and used only when a situation (for example, tight work area or restricted) deems it necessary. When stacking is needed because of site limitations, a hazard assessment or method statement shall be performed and the following guidelines considered:
Piling (for example, can be timber, concrete, H beam, or pipe) shall be stacked on level ground.
Piles shall have spacers, chocks or dunnage (that is, 4″ x 4″ timbers) placed between successive layers.
Piles shall not be stacked more than four layers high.
No employees shall step or stand on a stack of piles during unloading or stacking activities until the pile has been placed or set in its resting place, and spacers or chocks are properly secured.
Use of chocks are required for round or octagonal pile when there is a chance that the pile could roll if accidentally hit or weight being applied or placed on it would cause it the pile to roll.
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Augered/Cast-In-Place Piles
8.1 A daily inspection of all augering-related equipment shall be performed and deficiencies corrected before beginning any work.
8.2 The auger shall not be activated or moved while a worker is working on, ascending, or climbing the leads structure. The operator must not operate the rig; a “hands off” mode must be observed. The operator must take the signals from the worker doing the positioning.
8.3 When cleaning of the auger is taking place, the worker(s) must stand away 8 m (25 ft) from the rotating auger and use a piece of wood to clean the mud and debris from between the auger spirals. This area shall be identified (that is, with orange cones placed around the pile auger rig perimeter). Hard hats and safety glasses are required at all times as there will always be debris and clumps of earth falling off the auger during drilling activities.
8.4 It is very important to keep personnel out of the area where the auger is rotating. It will be necessary to have other equipment (for example, loader and backhoe) in the area to remove the excavated earth.
8.5 Care shall be taken when the exposure to concrete and grout is possible. This means wearing long-sleeve shirts for protection of the skin as well as other cement-related exposure hazards.
8.6 A designated person who has clear lines of visibility of the area shall guide concrete trucks delivering concrete or grout mixture into position.
8.7 During the insertion or removal of auger sections, the auger shall be adequately blocked or secured to prevent injury from equipment slipping or sudden movement.
8.8 All hoses for air and/or hydraulics supply, grout injection shall be adequately supported to prevent any sharp bends or kinks that could lead to a weak point and cause a release of the hose. Proper restraining devices are required at all connections.
8.9 Acceptable methods shall be provided to allow proper placement and centering of any steel-reinforcing cage installed in the piles. Extra care shall be taken to hold cages in place and not to over-exert any individual involved. Mechanical assistance, for example, crane, is required.
8.10 Lifting or carrying of pump hoses as well as other materials may present serious strain exposures to personnel. This potential hazard might also be magnified by muddy or slippery conditions. Adequate numbers of personnel and mechanical equipment, for example, forklift and crane, shall be required.
8.11 When project specifications require inspection of the internal soil conditions of a freshly augered pile hole, the contractor shall prepare a method statement for review by the Air Products representative. This method statement shall address proper safety precautions to be taken for the inspector to enter the hole or confined spaces as well as an alternate plan (for example, video camera and mirrors) that does not allow a person to bodily enter the hole. The preferred method is to not enter the hole. Under no circumstances shall entry into pile bores less than 750 mm (30 in) in diameter be undertaken.
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MISCELLANEOUS
9.1 Only personnel absolutely required to be close to the leads and hammer (to verify pile plumbness or location) will be allowed in the fall zone. All other personnel will remain 1 1/2 pile lengths away from the rig; for auger piles a minimum of 8 m (25 ft) is required. Checking piling for plumbness during driving must be kept to an absolute minimum. When working in an operating facility, the area must be roped off to limit access. This includes third-party inspectors and other visitors.
9.2 Keep loose material and tools out of the leads.
9.3 Falls, slips, and trips at grade are a common hazard that must be addressed as follows:
9.4 Eliminate the need to walk on or over piles, pipes, timbers, or planks.
9.5 Open pile shafts left unattended for an extended period of time (that is, before concrete placement or installing reinforcing steel) or under construction shall be guarded by a guardrail system or completely covered with an appropriate cover. A rigid or hard barricade shall be installed on three sides of the opening a minimum of 1 m (3 ft) away from the auger. These barricades shall remain in place until the concrete has been placed. When covers are used, they shall be capable of supporting, without failure, at least twice the weight of employees, equipment, and materials that may be imposed on the cover at any one time. All covers shall be secured when installed so as to prevent accidental displacement by the wind, equipment, or employees. All covers shall be color-coded and marked with the word “HOLE” to provide visible warning of the hazard. To prevent confusion when the cover (that is, plywood) is not being used, it should be leaned up against a pile on edge instead of being laid on the ground.
9.5.1 Open pile holes and/or holes created from piles that are driven lower or beneath the ground surface shall also be covered to prevent a person from falling into the shaft. Another method can be filling the created hole with soil level to the surrounding surface.
9.6 The contractor must furnish adequate hearing protection for their employees. Hearing protection is required when noise levels exceed 85 decibels. Earmuffs are required when the noise levels exceed 110 decibels. Warning signs alerting other personnel of high noise levels must be posted. These requirements shall be according to governmental regulations.
9.7 All hoses used must be equipped with the proper manufacturers’ restraining device for cranes or rigs that have been modified to accommodate an air compressor to the frame or body. These restraining devices shall be of adequate size and strength for the size, pressure, and volume of equipment being used.
9.8 Before commencing piling activity, a survey of the work area shall be performed to identify any underground obstructions or utilities, piping; conduit is present that could cause a safety incident. The contractor and Air Products representative shall discuss the need for safety and/or excavation work permits and institute the program accordingly. This discussion shall address the need for permitting when working in an operating plant, adjacent or near operating equipment or a green field site.