Fundamental Study on Rope Damage Reduction Using Intermediate Transfer Floor of High Rise Buildings

Lifts are essential for means of vertical transportation. In recent years, high rise buildings have become higher, leading to higher lifts and longer lift ropes. High-rise buildings have a longer natural period than conventional buildings. As lift ropes become longer, the natural period of the lift ropes become longer as well, and get closer to the natural period of the building. Consequently, the lift ropes are hooked to the equipment in hoistway when the lift ropes vibrate by an external force, such as a strong wind and earthquake. Secondary damage such as containment of passengers and lift service stop may occur. It has become a problem. For example, The 2011 off the Pacific coast of Tohoku Earthquake, 2215 cases such as catch and damage of lift ropes have been reported. However, operations of lifts after earthquakes are required. Therefore, this study constructs an analytical method capable comprehensive analysis. We aim to build a method to prevent catching by vibration reduction measures of the lift ropes. In this report, we examine the effectiveness of lifts using intermediate transfer floors for damage reduction of ropes. In the analysis, the maximum displacement of the main rope and compensation rope was examined when the lift travel is divided into two and four. The calculated results of the analysis confirmed that dividing the lift travel reduces the response of the main rope. On the other hand, the response of compensation rope was reduced by finely dividing the travel. It was confirmed that dividing the lift travel is effective for reducing the response of the rope.