Civil & Earthworks

Civil packages are won or lost on ground conditions, so the geotechnical report is the first document in the enquiry. It tells the contractor whether the site is rock, sand, sabkha or fill, where the water table sits, and whether the soil is aggressive to concrete. Those answers set the excavation method, the dewatering, the foundation type and the cement.

Ground varies sharply across the Kingdom. Coastal sites at Jeddah, Dammam and Khobar can sit on sabkha with a shallow water table and salts that attack concrete and steel. Madinah sits near basalt lava fields, where excavation turns into rock breaking. Riyadh is mostly limestone and sand, firmer but dry and dusty. Earthworks are tested rather than assumed: modified Proctor (ASTM D1557) sets the target density and field density checks confirm it layer by layer.

Concrete is designed and detailed to ACI 318, with ready-mix to ASTM C94. Where the soil report calls for it, sulphate-resisting cement (ASTM C150 Type V) and a protected mix are used below ground. In summer, ACI 305R hot-weather practice governs: concrete temperature at placing, curing started early, pours timed for the cooler hours. Test cylinders (ASTM C39) or cubes (BS EN 12390-3), as the specification names, are cast and the results recorded against each pour.

The package then climbs. Ground slabs come first, then reinforced concrete columns, beams, slabs, shear walls and stairs under loads from SBC 301. Underground utilities follow: storm, sewer, water and fire mains in HDPE, GRP or ductile iron, with manholes and duct banks, tested by pipe type. Boundary walls, retaining walls and waterproofing close the scope, with flood tests recorded before the waterproofing is covered.

Send the geotechnical report, the foundation and structural drawings, the BOQ, the site city and the programme. The offer states how it treats rock, dewatering and imported fill, since those are the lines where civil packages change.