BASICS OF MICROTUNNELING MOBILISATION FOR SAFETY OFFICERS TO KNOW
Safety
What shall a safety officer to be aware before the setting up of micro tunnelling are; a design, procedure, method statement, risk assessment and job safety analysis. The documentation shall be prepared by the construction management team and safety team to be familiar with the procedure and shall review for any missing item. The information below will help to give you a general knowledge of micro tunnelling but are not limited to for improvement safe practices.
Associated activities for the setting up of micro tunnelling:
All the associated activities have discussed here for the setting up of micro tunnelling which gives you an insight into the hazards and the risk involved in the setting up process. The bellow information could be used for the preparation of method statement and risk assessment. This section mainly focused on the process nor discussing any hazards and risk involved.
Excavation of shaft for the boring entry and exit pit. The depth of the excavation is depending on the depth of tunnelling to be started. General excavation safety measures which must consist of the soil condition to adopt the suitable protection form edge collapse. The size of the excavation shall be decided considering safe access (preferably stairs), adequate space for liftings, Mechanical ventilation (Ducts), pipes and hoses etc.
Lifting process comprises setting up of crane, equipment, control cabin, panel, tanks, pumps, pipe, generators and other supporting items operated around the excavation (soil stability and a safe distance to be upheld from the excavation before installing). And lifting and lowering of tunnelling equipment, components and other items for micro tunnelling to the shaft. Selection of crane shall be the weight to be lifted in view of its angle, radius and total weight while it safe positioning at the edge of the excavation. Lifting and lowering into shaft will continue till the completion of micro tunnelling this might embrace the use of man basket.
Entry into the excavation/shaft. Excavation is considered as confide space considering depth, width, the equipment used in and around the shaft. Mistily the shaft for the entry of tunnelling bore is made very deep up to 20 meters or more to bypass all other underground utilities. Change of oxygen deficiency and build-up of toxic substance and fumes are unavoidable since all the procedural requirement and best practices to adhere to. Further, once the tunnelling process is started there could be continuous visits for installation, inspection, maintenance or any emergency to attend.
Assemble and installation of equipment and networks in and around the shaft which required moving and fixing of heavy machinery, manual handling, hot works, night works, movement of plant and equipment, electrical and mechanical installations, erection of structured, etc. Subsequently, the installation process will continue in the shaft for the tunnelling placing the heavy machines. This process will last to the end of tunnelling works for installing heavy tunnel ring, periodic maintenance and repairers (recommend a dynamic risk assessment).
Work at heigh to the shaft mostly requires here for the installation of slurry pipes, hydraulic hoses, Ducs, access etc consisting the use of scaffold a working platform and for short and light works using man basket and lifting. The work at height covers the erection of access of shaft.
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