6-Method of Approach Pipe.pdf

Project Plan Narrative for Pipelining

SWSW will utilize HDPE piping with a fused bell and spigot ends manufactured by Snap-Tite for use in slip-lining pipe. SWSW plans to install pipelining in the following order: Southeast District, Southwest District, Southcentral District, Northwest District, and Northeast District. Pipe will be delivered to the local ADOT maintenance yard closet to the work location. Crews will coordinate with ADOT prior to any work to determine project schedule, water availability for hydrovacing, traffic control and any additional coordination that may be required.

The step-by-step procedure for pipelining is detailed below:

1. Verify Pipe Location and Size: SWSW will verify pipe location at the provided mile marker. SWSW will determine existing cmp diameter and length. Pipes will also be verified for hydrovacing. SWSW will order Snaptite based off of this investigation.

2. Hydrovac pipes: SWSW will coordinate with each district ahead of time to determine Traffic control, water needs (ADOT provided) and predetermined dump sites. Riley industrial will hydrovac each pipe with SWSW supervision.

3. Pipe Staging: Pipe will be loaded from ADOT yards and hauled to pipelining locations. This work is performed with a two-man crew, 3500 haul truck and goose neck trailer.

4. Lining of the pipe: Crews will begin by determining which side of the pipe has the best access with littlest amount of ground disturbance. The snaptite pipe is pushed into the existing cmp by connecting the bell and spigot ends together (Snap-Tite Joints) with the manufacturer provided rubber gaskets and lube.

SWSW will utilize a combination of come-alongs, chain hoists, straps, and equipment to ensure the pipe is snapped together appropriately. The pipe is then pushed through with a backhoe/excvator until it sticks out 12” on the other end. The excess pipe is then cut off on the end it is being pushed, leaving 12” as well.

This work is performed with a four-man crew consisting of a Foreman, 3500 w/gooseneck trailer, two operators, and one laborer.

5. Bulkhead: Based on the size and length of the pipe run, multiple PVC pipes are installed between the snap-tite pipe and existing cmp. Generally, a total of 4 pipes are installed ranging from 25%-80% of the total pipe length. These pvc runs will act as a grout tube to pump grout and fill the annular void. A shorter piece of PVC pipe is installed at the opposite end of the grouting operation to provide air venting and obervation. Bulkheads are constructed at the ends of the pipe allowing for the PVC pipes to stick out for grout placement. The bulk heads are constructed with 4000psi rapid set quickcrete that is mixed onsite.

The bulkheads are hand placed, 12” thick, between the Snap-tite pipe and existing CMP.

6. Grout: A towable trailer mounted grout pump is hooked up to the 2” PVC grout tube pipes. Ready mix trucks, with approved flowable grout are ordered. Once onsite the grout is placed using the ready-mix truck shoots into the grout pump. The pump then slowly places the grout through the installed grout tubes. Grout begins to fill the void until the annular space is filled. This is verified by the grout being pumped out the vent tubes as well as comparing to be calculated volumes. Once fully grouted, the grout tubes are cut off flush with the bulkhead. Additional concrete is added to the bulkhead to give it an aesthetically pleasing finish. This work is performed with a three-man crew consisting of a foreman, grout pump, one operator, and one laborer.

7. Squash Pipe form Removal: If squash pipe is required at a location, once installed the formwork will need to be removed from the hdpe. SWSW will utilize pole saws and staps to remove ths form work and haul to the dump.

8. Cleanup: Prior to demobilizing and moving onto the next location. Crews will remove all construction debris and any miscellaneous concrete. The result will look like no work had been performed but will have an obstruction free flowing drainage pipe. SWSW will have the local district approve of all work prior to demobilizing.