Geo Tech

In an effort to expand their research and development (R&D) facility, AstraZeneca under-took a $100 million expansion including construction of four new building wings in addition to the five currently completed.

The new building wings included a fully enclosed bridge building which crosses a brook, to facilitate indoor pedestrian and utility passage between buildings. In order to maintain continuity amongst finish floor elevations between the buildings, cuts on the order of 10± to 60± feet were performed in some locations within 30 feet of the brook. Geotechnical engineering studies were provided for the R&D building expansion project. Subsurface conditions on this steeply graded site generally consisted of shallow glacial till soils underlain by bedrock. Soil depths above the bedrock were observed to be up to 10 feet. As a result, a majority of the cuts at the site were assessed to occur in bedrock.

Accomplishing the cuts and constructing the buildings in close proximity to the wetlands buffer zone adjacent to the brook and in proximity to other limits of work represented significant challenges for the project. Engineering recommendations were developed to accomplish rock removal actvities in a manner to create "stable" slopes, mitigate disturbance to AstraZeneca's ongoing R&D operations, and establish slopes within the proposed limits of work. Engineering recommendations were developed to support the building additions using shallow spread footing foundations bearing primarily on bedrock.

The buildings were designed to be constructed below proposed finish grades with exception of the bridge connection building. Recommendations for installation of underdrains were developed to mitigate the potential for groundwater buildup behind building basement walls and beneath slabs on grade. A test blast program was developed to assess the site vibration propagation characteristics in response to blasting. The test blast program was implemented to allow the AstraZeneca science community to assess whether blasting activities might negatively affect ongoing R&D activities. The test blast program allowed the project team to develop a production blasting program designed to mitigate potential building damage and interruption to ongoing activities.