The construction works of a two span (2 x 13.4 m) bridge for a main road, across a natural stream is in progress. The embankment filling for the road on the two sides has been done. Excavation for abutments and pier, the two concrete abutments with capping beams on top of each, the mid concrete pier with the pier cap, and the bridge deck using pre-stressed beams (13.4 m long x 4.2 t), to be constructed. The depth of excavation is around 4 m. The bridge beams have to be transported from the pre-cast concrete yard located 5 km away from the site. After placing the pre-stressed beams, the bridge deck to be constructed with grade 25 in-situ ready mixed concrete, which should also be transported from the batch plant installed at the same concrete yard. Concreting works of the bridge deck to be carried out continuously without a break in one operation.
(a) Prepare a list of construction equipment needed for the completion of the works mentioned above, stating the purpose of deploying each type of machine.
(b) The sides of deep excavations for foundations of abutments and pier have to be protected from possible failures. What is the method you propose to protect such sides of excavations?