I wandered around my area last week and looked at some of the construction sites for the second phase of the Incheon Airport railway line (which I've looked at here and here). For more photos of the construction, as well as what it's like to ride the completed railway between Incheon and Gimpo airports, Jon at I'm a Seoul Man has numerous posts here (and here).
Below is a map of the route through my area, with the Incheon line being yellow, and line 9 being green.
I biked around the southwest corner of the Magok field, above, many times last summer, and remember riding past some greenhouses one evening after it rained and hearing a chorus of frogs. I knew in a few years they'd be paved over, but I didn't expect that to happen in just a few months...
You certainly can't ride past those greenhouses anymore. Behind that wall is the construction for the railway. The first photo looks northeast:
The next two photos are from the other end, and look southwest:
In the photo below you can see, running across the picture, the (now covered) excavations for line 9, while the Incheon rail line can be seen curving at bottom left.
It eventually runs under Yangcheon-gil and and rises out of the ground. Below is where its ascent will begin:
It then follows a 400-500 meter ramp. Below is a photo taken from the top of the ramp looking at the bottom:
Turning around and looking towards the river (and the Olympic Expressway), you can see steel spans which are supported by concrete piers.
Since the pier below is exposed, it gives a better idea of what the entire pier looks like.
Below, several spans wait to be lifted into place by the crane.
Here, two piers on either side of the expressway stand before the bridge, which is barely visible.
The photo below gives a better idea, as you can just make out the crane and one pier on the otherside of the expressway, as well as the bridge.
Below is a view of the bridge from the west; it appears to be half finished.
Last, from the top of a nearby mountain, looking west, we can see the rail bridge, the Banghwa Bridge, and the Haengju Bridge.