FREE earthquake NBS rating peer review
Many NZ Buildings Are Earthquake Prone
“We all know New Zealand is extremely susceptible to seismic activity,” explains Dr Jing. “Unfortunately, much of our building stock is ‘earthquake-prone’. This means a building is rated at less than 34%NBS and it will have its ultimate capacity exceeded even in a moderate earthquake. If it collapses, injury or death is likely. As a seismic engineer, this is of great concern to me – I want to keep people safe. Property owners should want to protect their investment and keep their tenants safe. At Tino Seismic, we believe by doing the work we do, we can make New Zealand safer. Ultimately, this means we can save lives.”
“Property owners should want to protect their investment and keep their tenants safe.”
Reviewing earthquake NBS Ratings
In reviewing the design work of other engineers, Dr Jing knows there is room for massive improvement in the seismic assessment and retrofit of our buildings. He is regularly called upon to peer review earthquake NBS ratings and seismic retrofit designs for engineers, property owners and investors.
Proposed retrofit solution at one particular floor
“I’ll give you an example,” he explains. “Recently, an engineer assessed a 1980’s two-storey supermarket
“Many NZ buildings are earthquake prone and most NBS ratings are either under- or overestimated.”
with a carpark on the first floor. They reported a seismic rating of 67%. However, when I completed a review of this assessment, the building was found to have a rating of just 6% because the original engineer incorrectly calculated the tensile capacity of the floor slab. We designed a solution that subsequently strengthened the floor to meet 67%, which is a much safer outcome.”
Seismic Retrofit Design Solutions
John has assessed and retrofitted many noteworthy heritage and commercial buildings across New Zealand and has been involved in more than 800 projects. “Let’s take a look at a seismic retrofit design solution,” says John. “This building is one of the oldest and most significant churches in New Zealand, with a Category 1 heritage status. To seismic retrofit the church, the original engineer designed extensive steel framing for the church’s interior. This was rejected by the client as it would ruin the church’s ornate aesthetic features”.
Tino Seismic utilised the existing unreinforced masonry structure in-situ by allowing it to rock to dissipate any devastating earthquake energy. “With this solution, we were able to preserve the church’s precious heritage architecture, much to the relief of the client and the community”.
Retrofit Work Completed While Building Occupied
A second retrofit solution features a four-storey reinforced concrete office and warehouse built in the late 1900s. It had an NBS of less than 34%, so it was earthquake prone. Dr Jing designed a solution to bring the seismic rating up to at least 75%. Marc Stewart of BBR Contech explains. “We engaged with Dr John Jing on the seismic upgrading of a multi-storey commercial building in Auckland utilising retrofitted posttensioning and CFRP (Carbon Fibre Reinforced Polymer) to increase capacity of the building’s slabs. Working with John meant we could offer a solution that allowed our client’s tenants to maintain the occupancy throughout the construction period”. A win-win all round.
Get a Free earthquake NBS rating peer review
If you’re a commercial property owner, investor or buyer and you have received a New Building Standard (NBS) rating for your property and would like it peer reviewed, John will check it for you.
Our peer review process involves a high-level initial review (all our clients receive their first initial review for free), followed by the identification of high-level issues that require immediate attention. We then carry out parallel calculations and analysis to verify the results and provide actionable recommendations.