Lara will walk out into another yard. You need to cross it to reach the next part of the complex. Go straight ahead and turn left.
Walk over the plank towards the collapsed bridge.
There is a bottleneck past the footbridge. Lara will start to shimmy along. After she reaches the edge, jump over to the bridge and turn right, where you will have to jump over yet another chasm.
Again, pick the explosive arrow and shoot it at the junk that is blocking the gate. On the next yard, you will fight some more Trinity soldiers.