MirHossein Farhangi - Civil Engineering Student, Structural Tendenc, Tehran, Iran,
Farzaneh Moradpour - Occupational Health of Urmiauniversity author,Tehran,Iran,

Microtunnel boring machines are very similar to tunnel boring machines (TBM) but on a smaller scale. These machines generally vary from 0.61 to 1.5 meters (2 ft 0 in to 4 ft 11 in) but smaller and larger machines have existed. Usually the operator controls the machine from a control room on the surface of the ground. The Microtunneling machine and jacking frame are set up in a shaft at the required depth. The operator is given constant feedback about the machine’s location, orientation and hydraulic devices via a computer console or CCTV camera. Most machines also have video cameras set up to enable the operator to monitor activities in the jacking shaft and at the separation plant. The operator controls the MTBM1 and the jacking frame from the safety of the control room which is usually situated on the surface, next to the jacking shaft.[1] In this paper, the occupational hazards of Construction of Surface Water Collection Pipeline using micro-tunneling method in different situations quantitatively are discussed. Hazard assessment in the workgroup of the project s job hazard model is a developed model of tunnel construction. This model can assess the hazard at the company and organization, activities, work and the overall hazards of the assessment project. twenty job positions have been defined for this project, such as drilling machine operators, loader, excavator, spraying machines, and crane operators, welder, supervisor of project, truck drivers and other workers participating in this stage of construction. All the workers hazards are quantitatively specified and their jobs ranked according to their hazard. The hazard factor for the two major stages in the construction of concrete pipelines has been evaluated including a) drilling and initial support and b) final coverage.

Micro Tunneling, pipejacking, Occupational risks, The mechanism of guard structures