Building a campus

In our July 2019 newsletter, we talked about the challenging design of Islamabad Mosque at the 10.3 ha Tilford the Ahmadiyya Muslim Association (AMA) site. In addition to the Mosque, a range of buildings was developed to create a campus environment for the AMA. These include new residential and teaching accommodation as well as a multi-purpose hall which provides facilities for sports, recreation, dining and assembly.  

SOLID has provided the civil and structural design for the whole development.  On the civils side we completed the roads, earthworks and drainage for the whole development.

Road design & car parks

The site’s road layout was divided between areas where different road loads are likely to enter. Not all roads were expected to carry heavy vehicles. This allowed for shallow excavations and sub-bases in lighter trafficed areas that created a saving in the overall project costs.  A full 3D terrain model was completed for the site. The design of the 1.3km of private road was completed using ALLPlan civil 3D and tracking software.

The 100 parking spaces distributed across the site were designed using tanked permeable surfaces. It incorporated geotextiles that allowed for bacterial growth, which in turn break out hydrocarbons.

All water from the parking bays were discharged to petrol interceptors and then into the ground via soakaways. The site is within a source protection zone i.e. in the proximity to a public borehole that is used to provide portable water.  We therefore had to obtain approval of our design from the Environment Agency

Excavated material

SOLID completed the full 3D cut and fill calculations for the development.  We prepared the planning application for terracing the cut and fill area at the back of the site and managed the CL: AIRE Application for materials management and verification.  The total excavated material for this site was in the region of 9,000 m3. All excavated material was retained on site. The terracing of the excavated material formed an elevated swale.

Surface water drainage

The site had very good infiltration rates; however all water required a train treatment before it could be infiltrated.  The train treatment consists of discharging water into permeable surfaces and then moving it across different silt traps with a final discharge into an infiltration basin or swale. The site was divided into three areas. The main infiltration basin has a 650m3 storage capacity. The swale formed as part of the terracing of the excavated material, has a capacity for 350m3. The third area has a small swale with a capacity of 50m3.

SOLID facilitated meetings with The Environment Agency and the Lead Local Flood Authority for the approval of the surface water drainage design.

Foul water drainage

The site had to stay operational for the duration of the project. As part of the project one building had to be operational. SOLID scoped and determined the foul sewer rehabilitation scheme. The sewer for the operational building was rehabilitated in different stages. Rehabilitation included excavating and replacing pipes and lining of sewer sections. The new foul sewer system connected to this existing drainage.