Highest Shear Wall Multiplier Approved for P&B Midply
The “Shear Wall Multiplier” is the seismic resistance indicator specified in the Japanese building code (Building Standard Law: BSL). This allows architects to simplify the structural confirmation of shear walls against lateral force when they design small-size buildings such as 2-storey houses. In addition to those specified in the BSL, shear wall multipliers can be given by MLIT* when their performance can be demonstrated by testing.
The Midply Wall System (MPW) was originally developed for PFC buildings. However, industry has shown interest in adapting MPW as an effective as shear-resistive infill element for post and beam housing to drive further market penetration in this segment. As part of the Canada Wood Japan market access projects in FY2017-2018, we conducted the shear wall tests for a P&B MPW solution. The test data were submitted to Centre for Better Living, one of the MLIT designated performance evaluation bodies. Dated April 6, 2018, based on the evaluation committee’s advice, MLIT approved a shear wall multiplier 5.0, the maximum value allowed in the ministerial approval system. With this MLIT approval certificate attached to the building permit application, the P&B designers can now enjoy the efficient measure of building with high resistance against lateral forces. It is worth noting that this infill system is also useful for seismically resistive renovation of existing homes.
*Note: Ministry of Land, Infrastructure, Transport and Tourism