Paddy and Water Environment | 2021
Damage characteristics of conduits in irrigation earth dams
Abstract
In this study, we report the damage characteristics of conduits in irrigation earth dams based on the surveys conducted on four dams with different conduit types (cast-in-place and precast types) and diameters (600–1000\xa0mm). The damage condition (cracks, leakage, and joint separation) and the deformation of conduits were observed using a self-propelled measuring system with an inertial measurement unit (gyroscope and accelerometer) and a CCD camera. Results reveal that cracks were scarce in conduits, and most conduit deformations were accommodated by the joint separation. In particular, in the precast conduits, because the number of joints per unit length was more, the deformation tended to be allocated to several joints. Moreover, settlements of conduits were not simply convex in accordance with the overburden pressures but were significantly affected by intake structures and structural cutoff walls. Although, in the future, it is necessary to develop conduits with joints having both high sealing performance and flexibility, the results obtained from this study will provide important knowledge for this development.