First photo shows Rebar metal support stands providing an angled grade to the longitudinal (parallel to the spillway) drain pipe. From a water flow perspective, this drain pipe is angled downward (downslope) even though the image gives the impression of an upward angle. The separation of the angle to the lower fill concrete base, with respect to the drain pipe, is from the sharper downhill grade of the spillway.
This longitudinal drain pipe likely connects to multiple "across the spillway" drain channels just as shown where the construction worker is filling in a drain channel with filter gravel. Inside this filter gravel is a large pipe that is perforated to allow collection of any seepage water (from any seepage above or below the pipe).
The second photo is the prep work underway at the junction to the lower spillway construction concrete section to the RCC start section. Long anchor bolts and plates have been emplaced at an angle to transfer anchorage into a wider area of the thick RCC section (right). Another row of anchor bolts and plates are lined up in the construction concrete (left). Thus, both sections will share in the anchorage in the soon-to-be poured construction concrete to fill this gap. The mini-excavator has an attachment to pulsate and hammer a steel pointed tip to form the desired gap shape (widen the base). An additional photo shows a large group of workers hand removing the chunks and cleaning this seam area from leftover debris.
We'll see later how they intend on handling the expansion/contraction of the additional layer of chemically hardened RCC layer and the construction concrete layer, and any re-inforcement steel that will straddle this junction seam area, to match up with the finished surface grade of the spillway.
Photo 1 - Rebar metal support stands providing an angled grade to the longitudinal (parallel to the spillway) drain pipe. From a water flow perspective, this drain pipe is angled downward (downslope) even though the image gives the impression of an upward angle.
Photo 2 - Prep work underway at the junction to the lower spillway construction concrete section to the RCC start section. Long anchor bolts and plates on both concrete sides to facilitate securing this concrete pour for the junction. Mini-excavator "widening" the lower base area of the "V"
