There is an increasing demand for longer, deeper and narrower curvature driving techniques for non-man-entry microtunneling methods. As it is essential to measure the exact position of the machine during curved driving, a unique measuring method known as the "electromagnetic induction method and pressure differential method" (hereinafter "electromagnetic method") was developed for the Acemole method. However, the electromagnetic method was limited by a number of factors, namely limitations of ground depth, limitations of noise levels, and the necessity for measurements to be taken from a vertical position. To solve these problems, a new measuring technology "prism" was successfully developed. "Prism" measures the rear of the driving machine by emitting a laser from the start pit and bending it to the desired angle. The technology was introduced at No-Dig Brisbane 2006. This paper explains the development of the technologies after No-Dig Brisbane. The three main developments since No-Dig Brisbane are as follows. 1. Movable type: Development of a moveable prism unit allows the prism unit to be placed at the exact curving point. 2. Laser relaying unit: Development of a laser relaying unit has enabled longer distance measurement. 3 Remote support system: Data can be sent real-time from the site to a remotely located expert to enable effective and efficient use of technician expertise. As a result of these technical developments, the Acemole method has succeeded in driving 264.7 m in length and 25.6 m in ground depth. This paper will also cover two actual construction reports.
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