Construction planning of microtunnelling works in urban areas

Microtunnelling a new sewerage pipeline or tunnel underneath densely built-up urban areas is more reliant on early planning than many other civil works. The nature and constraints of urban microtunnelling effectively fix key project details considerably before construction commencement, with little subsequent flexibility. These early constraints arise because of the high degree of interconnected and repetitive construction activity sequencing, and the high capital outlays for the precast production and microtunnelling machine. Based on the author’s work on eight microtunnelling projects in Singapore, this paper proposes and discusses 11 steps of construction planning elements which have been observed as critical to expeditious cost-effective project outcomes.