The previous Detailed Seismic Assessment (DSA) was carried out in 2017. MoJ were prompted to update their DSA following the release of the November 2018, Ministry of Business, Innovation and Employment (MBIE) Technical ‘Yellow Chapter’ Guidelines on the seismic assessment of existing buildings.
The new assessment guidelines identified the precast floor and first floor slab as areas of concern. Assessment to the new 2018 ‘Yellow Chapter’ version of the MBIE guidelines indicated the floor slab (or diaphragm) potentially had a rating of less than 34% NBS at Importance Level 3. WSP recommended the initial securing works should be given a high priority.
The scope of the project included urgent seismic strengthening to the level 1 floor slab and other design works associated with the seismic upgrade.
During the design stage the MoJ took the opportunity to increase the scope to include other minor works as described below:
- AVL upgrade for courtrooms 1 & 2 (initially programmed for 2021).
- Upgrade of customer service counter to current security standards.
- Building envelope and façade repairs.
CLIENT BRIEF/PROJECT CHALLENGES
The MoJ closed the courthouse in November 2019,following the findings of the updated DSA. Staff and operations were relocated to enable the works to be expedited. Following completion of the strengthening work, the building will return to its previously assessed rating of 50% to 55% NBS IL3, (65% to 70% NBS IL2).
The Levin District Court is an operational court in the Horowhenua-Kāpiti region. All staff and operations were moved from the Court to other Courts in the Wellington and Manawatū regions. To reduce ongoing costs and return Court services to Levin, MoJ was required to act quickly to complete the work.
WSP provided a seismic strengthening design solution for the floor diaphragm, and for the bolted end connections to the steel beams that support the first floor and the precast concrete walls. The WSP design was fast tracked going straight into detailed design.
WSP provided a fast-tracked solution, which minimised the court closure time, enabling court operations to return to Levin in a timely manner. WSP also managed the delivery of the project within a compressed construction programme of three months. The project was able to incorporate a change in scope to include, an AVL upgrade, anew reception area and building façade improvements, all within the original baseline programme.
LIST OF PRIMARY SERVICES
The WSP team provided Structural, Architectural, Building Services and Fire Consultancy as part of its design service. WSP also provided Project Management services from commencement of the project through until close out. These services included Engineer to Contract and Construction Management.