Dyson Village, Malmesbury
We are the structural engineers for this truly component-based cross-laminated timber (CLT) project which provides accommodation for students of the Dyson Institute of Engineering & Technology in Malmesbury. Each module, or ‘pod’ is approximately 7.5m x 4.0m in plan and provides a fantastic working environment for each years' cohort of students.
The pods, of which there are 78, are arranged around a central bund and are stacked one on top of the other, resulting in many cases with a ground floor pod supporting a cantilever pod, built off a cantilever pod and on four occasions, the uppermost pod is rotated through 90 degrees - some serious structural gymnastics.
The pods comprise cross-laminated timber (CLT) construction throughout and are delivered to site (almost) fully clad, allowing for a rapid construction programme and greatly reduced site works. The primary inter-pod connection is made on site and comprises only four bolts, which can be adjoined in less than 10 minutes by one operative.
Due to the unusual arrangement of pods and form of construction generally, we used finite element analysis to determine the distribution of forces and stresses across the system, using the output to carry out detailed design checks on each of the key elements across the structure. The analysis of CLT is challenging as it comprises layers of timber glued in two orthogonal directions, resulting in varying stiffness in three directions that has to be captured numerically - orthotropic stiffness matrices were implemented within our analysis to accurately capture this behaviour. We worked closely with the design and build manufacturer of the modules to ensure the solution was suitable from both a structural and buildability point of view.
As part of the design process for seviceability checks, the University of Edinburgh were commissioned to carry out vibration and modal testing of a 'prototype' building to ensure the end-users would not feel any discomfort due to in-service movements.
We also carried out full-scale load-deflection testing on the prototype ‘triple stack’ to ensure that the boundary conditions adopted in our finite element model accurately reflected the as-built condition.