Memorandum: Culvert Assessment - E&N Rail Trail Construction (McElhanney)

Sta 0+766 - 500mm dia culvert (main)

The existing culvert at Sta 0+766 is a 500 dia vitrified clay pipe running under the rail line from south to north. The existing pipe is broken throughout its length on the quarter points, with clear separation at the breaks and root intrusion. Underneath the rail line the pipe is severely deformed, with the vertical diameter approximately 60% of the horizontal diameter. Potential of collapse of the pipe is high.

The existing manholes on both ends are non-standard. The base consists of randomly placed boulders between the inlet and outlet pipes with a concrete box frame above with rectangular lids.

Replacement of this pipe and manholes is recommended.

Sta 0+947 – 300 mm dia driveway culvert

The existing driveway culvert at 0+947 is a 300 mm dia concrete culvert running south to north. There was some accumulated debris / cobbles inside the pipe prior to flushing. There are minor cracks at a couple of the joints, though there is no evidence of root intrusion. The joints do not appear to be gasketed and some water is leaking from the culvert into the ground. Near the north end of the culvert there are some cracks along the pipes reinforcing. This section of pipe is being removed based on the current trail design.

As there is no construction above this culvert, except where we tie in, and it is in good condition, replacement is not recommended.

Sta 1+055 – 500mm dia culvert

The existing culvert at Sta 1+055 is a 500 dia vitrified clay pipe running under the rail line from south to north. The existing pipe is broken throughout its length on the quarter points. Vertical deformation of the pipe is visible for the section beneath the rail line. The vertical diameter is approximately 75% of the horizontal diameter. Water infiltration from the top of the pipe was evident in the video with steady streams of infiltration. North of the rail line the pipe is not visibly deformed though cracks at the quarter points continue.

The existing manhole on the north end is a standard manhole with a formed channel base.

Replacement of this culvert is recommended up to the manhole. Replacement of the manhole is not recommended.

Sta 1+133 – 300 dia culvert

The existing culvert at sta 1+133 is a 300 dia concrete pipe running under the rail line from south to north. The video was taken in the reverse direction from north to south. The northern most 10m is in good condition with minor fine root intrusion at pipe joints. At 10m from the north MH there has been a smaller diameter pvc pipe inserted into the concrete pipe. This pipe is approximately 200 mm in diameter. There are some sticks lodged in one of the joints at approximately 12m from the north manhole, the pvc pipe appears to be unseated at this joint, possibly due to the stick at the time of installation. At 15m from the north mh the pipe material changes to 300 dia vitrified clay. The vitrified clay pipe is cracked and the joints are separated. The pipe has started to deform.

Replacement of the southern portion of vitrified clay is recommended as a minimum level of remediation. The south most section of pvc pipe should be pulled back, the stick augered out and pvc pipe reseated with next pipe section.

Sta 1+760 – 600 Steel culvert

The existing culvert at sta 1+760 is a 600 dia steel culvert running from south to north under the rail line. The existing culvert is in moderate condition with early signs of corrosion on the bottom third. This is typical for a pipe of this age. There are no visible signs of deformation or root intrusion.

Replacement of this culvert is not recommended at this time.

This culvert assessment is based on McRaes Environmental Services Ltd. pipe video inspections completed for Allterra Construction in October and November 2014.

Ian McCall, P.Eng.