بکارگیری روش مهاربندی ACM جهت مقاوم سازی مجدد سازه های فولادی

ABSTRACT Application of ACM Brace Retrofitting Countermeasure to Steel Structure

It is well known in Japan that a lot of reinforced concrete story buildings built by some old earthquake resistant design codes before 1981 were destroyed in the 1995 Hyogoken Nanbu Earthquake. Therefore, Japanese Government has adopted several significant politics concerning this issue since 1995 in order to reduce a lot of earthquake damages for RC and steel story building structures (referred to as S building) built before 1981 as quickly as possible. As some seismic retrofitting policies adopted by Japanese Government had been not carried out smoothly, Japanese Government has been demanding a numerical target to quickly improve a seismic retrofitting ratio for all buildings by many local self-governments in Japan. This numerical target of seismic retrofitting ratio including RC and S buildings as well as wooden houses is 90% until 2017.

In general, a seismic retrofitting work for RC and S building structure using a typical steel br removal or temporary evacuation. It is more desirable and convenient for a lot of RC and S building owners that the seismic retrofitting work is conducted as quickly and economically as possible. It is therefore very important for structural engineer to propose a new retrofitting technique instead of X and K shape steel braces. At the present time, a seismic resistant performance of RC or S building structure is judged from a seismic index of structure, Is, evaluated by some criteria established by the Japan building disaster prevention association (Housing Bureau in the Ministry of Land, Transport and Tourism in Japan 2001; Japanese Structural Engineer Association 2006).

The number of steel brace required for the seismic retrofitting work of RC and S building structures can be decided to satisfy a given seismic judgment index value, Iso. The author has already proposed a seismic retrofitting countermeasure for RC building structure using an advanced composite material (referred to as ACM) bracing method (Takatani 2008 and Takatani 2011), which consists of a carbon fiber reinforced plastic (referred to as CFRP) material, steel sleeves and anchors, in order to save a lot of a large-damaged earthquake. It is well known that CFRP material has several advantages of strong and light-weight feature, good durability, and wide applicability in comparison with the steel material. In this paper, ACM bracing method is applied for the seismic retrofitting work of S two-story building structure instead of steel bracing method.