Abstract: In order to apply partially filled steel grid composite deck as the horizontal supporting structure of various kinds of infrastructures, the variation of its flexural strength according to design parameters such as cross and longitudinal bars constituting the steel grid and the type of shear connection is evaluated and compared experimentally. The result shows that the design sensitivity of the deck to the spacing of the cross bars is insignificant in the case of structure with low risk of punching failure or without load distribution problem. By means of shear connection composed by transverse rebar and longitudinal bar without additional shear stud bolts, the complete interaction between steel grid and concrete slab is able to be achieved and the composite deck can develop its bending resistance capacity.
Abstract: Recently, as the scale of construction projects has
increases, more ground excavation for foundations is carried out than ever before. Consequently, damage to underground ducts (gas, water/sewage or oil pipelines, communication cables or power cable ducts) or superannuated pipelines frequently cause serious accidents
resulting in damage to life and property. (In Korea, the total length of city water pipelines was approximately 2,000 km as of the end of 2009.) In addition, large amounts of damage caused by fractures, water
and gas leakage caused by superannuation or damage to underground
ducts in construction has been reported. Therefore, a system is required to precisely detect defects and deterioration in underground
pipelines and the locations of such defects, for timely and accurate
maintenance or replacement of the ducts. In this study, a system was
developed which can locate underground structures (gas and water
pipelines, power cable ducts, etc.) in 3D-coordinates and monitor the
degree and position of defects using an Inertial Measurement Unit
(IMU) sensing technique. The system can prevent damage to underground ducts and superannuated pipelines during construction,
and provide reliable data for maintenance. The utility of the IMU sensing technique used in aircraft and ships in civil applications was
verified.