I will choose the Cantilever bridge witch connect block c with the new building.

Cantilever bridge is an excellent bridge structure, since this structure only required the one side of each cantilever to support without the bridge Pier, it allows the vehicle or pedestrian over through from under the bridge, and does not affect the traffic on first floor.

The anchor arms can be directly attached to the two building, without the need for artificial support. Since most bridges contain multiple cantilever spans, we can use precast component to reduces the time required.

The most important part is these bridges can tolerate the effects of thermal expansion and ground movement better than others. Consider Singapore’s weather, we need ensure that the bridge structure does not deform because of exposure under sun and thus affect the stability of the entire expansion bridge.

Take into account the distance between the two buildings is only 30m, our bridges will not too long and will not very costly. Cantilever bridge is not suited to earthquake-prone areas, but Singapore do not have this problem.

The reason of why I did not choose Simple supported spans bridge is because it may be costly even for rather short spans, since expensive steel is required as a construction material. [3]If use concrete to build it, is not that strong to withstand the high tensile forces acting on the beams. As a result we need add some steel mesh to make it more stable.

The disadvantage of steel truss