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West Toronto Diamond Grade Separation: Canadian Transportation Agency Order

The CTA decision dictates ways and means of the types of equipment used for pile driving, how the equipment is used, and when equipment can be used. These restrictions will dramatically slow the pace of the work, and the overall project is anticipated to take five years (to fall 2014) to complete.

In accordance with the CTA decision, GO has restricted the use of impact hammers and hours of pile driving activity as the December 7, 2009 decision is outlined below:

"Giken Hammer:

  1. extend the use of the Giken hammer for the duration of the steel pipe pile-driving activities on the project and for more than the previously scheduled 250 piles. To that end, GO Transit is required to pursue an extension of the contract for the use of the Giken hammer with the supplier for the duration of the pile-driving activities. If GO Transit is not able to secure an extension to the contract with the supplier, GO Transit is to notify the Agency, the WTDCG, and the City of Toronto with an explanation of the reasons why it was not possible to secure the extension.
  2. use the Giken hammer in more sensitive areas.
  3. use the Giken hammer, in addition to weekday pile-driving activities, for pile-driving activities that take place outside the standard hours of 8:00 a.m. to 4:00 p.m. on weekdays."

COMMENT: GO is required to pursue an extension of the contract for the use of Giken. The current piling contract ends on March 31, 2010 and GO can, through our general contractor, continue to use Giken. Since September, GO has been using the Giken unit north of the Old Weston Road crossing, next to the National Rubber Technologies (NRT) building. Use of the Giken unit has been successful, but its progress is also very slow. It will take over six months (to the end of March 2010) to install the 250 piles, about 10 per cent of the total number of steel pipe piles for this project.

"PTC-Vibro Hammer:

  1. Within 14 days from the date of this Decision, use a PTC-Vibro hammer as the primary method to install the steel pipe piles by augering them, if needed and where possible, to complete their installation. Where complete installation with a PTC-Vibro hammer and augering is not possible, drive the piles to the maximum depth possible, considering soil conditions, with the PTC-Vibro hammer and only then use an impact hammer to finish the pile-driving activities. This does not preclude GO Transit from employing a conventional vibratory hammer in areas that are less sensitive to vibrations or where GO Transit can mitigate the impact of vibrations."

COMMENT: As of December 21, the CTA ordered GO to use the PTC vibratory hammer as the primary method to install steel pipe piles. This direction is being complied with where possible, although there are very few of the remaining piles that can be installed with this equipment. This is because the PTC vibratory hammer often cannot meet vibration limits set by City of Toronto by-laws or the restrictive limits set by engineers.

"Impact Hammer and Related Mitigative Measures

  1. use an impact hammer on the project only in conjunction with a PTC-Vibro hammer or where no other method is possible.

COMMENT: At a minimum, the impact hammer will have to be used to install the final one to two metres of the pipe piles as the PTC vibratory hammer cannot work close to or below ground level. Previous experience with the PTC vibratory hammer determined that it was often only able to install the pipe pile as little as halfway.

  1. where the impact hammer must be used, de-power the impact hammer and decrease the hammer energy wherever possible and use shrouds, skirts and rubberized chasers. If shrouds are opened, any opening must be positioned, wherever possible, down the tracks and not toward any residential area.

COMMENT: These noise mitigation measures have been in place since June 8, 2009.

  1. where the impact hammer must be used, employ moveable noise barriers, wherever possible, to deflect noise away from nearby residential areas by moving them to current pile-driving locations."

COMMENT: This is already in place, although noise barriers can only be used where they do not interfere with worker safety or train operator sightlines.

"Limited Hours for Pile-Driving Activities

  1. use the Giken hammer, the preferred method of pile-driving, between the hours of 7:00 a.m. and 7:00 p.m. on weekdays (excluding statutory holidays) and between 9:00 a.m. and 7:00 p.m. on Saturdays.
  2. restrict the hours of work for installing piles with the PTC-Vibro, conventional vibratory and impact hammers to between 8:00 a.m. and 4:00 p.m. on weekdays.
  3. negotiate agreements with the City of Toronto to allow for road closures such that pile-driving activities undertaken with the PTC-Vibro, conventional vibratory and impact hammers are limited to between 8:00 a.m. and 4:00 p.m. on weekdays.
  4. negotiate agreements with other railway companies to allow for train blocks such that pile-driving activities undertaken with the PTC-Vibro, conventional vibratory and impact hammers are limited to between 8:00 a.m. and 4:00 p.m. on weekdays.
  5. on those exceptional occasions when pile-driving activities must take place outside of the hours of 8:00 a.m. and 4:00 p.m. on weekdays and it is not possible to use the Giken hammer, the PTC-Vibro, conventional vibratory and impact hammers may only be used following 14 days prior notice on GO Transit's Web site of the proposed activity, including specific details of the constraints that preclude the use of the Giken hammer. In addition, GO Transit must report within its communication program the actual use of the PTC-Vibro, conventional vibratory and impact hammers."

COMMENT: All restrictions as noted in the limited hours of pile driving activities are being adhered to.

"Noise and Vibration Monitoring

  1. within 14 days from the date of this Decision, prepare and submit to the Agency, for approval, a proposed methodology for an enhanced noise and vibration monitoring program to provide weekly noise and vibration level measurements, including equipment to be employed, method of measurement and associated metrics, and the criteria for selecting the location of measurements.
  2. at the same time as it submits its proposal to the Agency, provide copies to the WTDCG and the City of Toronto, which will then have seven days from receipt of the proposal to submit their comments regarding the proposed methodology."

COMMENT: The CTA decision required GO to submit for CTA approval a proposed program for noise and vibration monitoring by December 22, 2009.

GO has retained the services of a specialist noise and vibration consultant who provided assistance with the development of the ordered noise and vibration monitoring program (submitted on December 21, 2009). The proposal for the terms of reference for this program has been submitted to the CTA, WTDCG and City of Toronto for review and comment. Comments were requested for December 29, 2009. As of December 29, 2009, the Agency has neither approved nor commented on the plan. The City of Toronto commented on the plan as of December 30.

Once the CTA approves the plan, the implementation of the required monitoring program will require two to six weeks beyond the approval of the program as submitted. This is due to the public tendering process and GOs ability to approve and secure a contract for the supply and installation of the noise and vibration monitors, the supply and installation of these monitors, in accordance with and when the terms of reference that have been agreed to.

The proposal for the terms of reference for this program has been submitted to the CTA, WTDCG and City of Toronto for review and comment. Comments were requested for December 29, 2009.

"Communications

  1. within 7 days from the date of this Decision, post on the current Web site and update daily all scheduled pile-driving activities for the project and their location, as well as any scheduled periods of inactivity (project plans) for a projected period of no less than 14 days from the date of posting, which project plans cannot be changed except following notice as set out in c) below.

COMMENT: Implemented on December 14, 2009.

  1. within 28 days from the date of this Decision, consult with the WTDCG and the City of Toronto, and implement, a more comprehensive communication program, which must include:
  • an enhanced Web site, which is updated daily, to communicate information to local residents and businesses including, without limitation, detailed information about the current pile-driving activities and associated equipment on the site; the project plans for a projected period of no less than 14 days from the date of posting, which project plans which cannot be changed except following notice as set out in c) below; and, the locations and projected locations of moveable barriers and any constraints that preclude the use of moveable barriers at any location; and
  • an e-mail address and phone line, both to be answered by a person knowledgeable about the project and its schedule, for residents and businesses to communicate particular concerns about the current and projected pile-driving activities and to which GO Transit must investigate and respond within 48 hours.

COMMENT: Implemented on January 5, 2010 with input received from the City of Toronto and individual community members, but not the WTDCG.

  1. in the event of exceptional circumstances which necessitate a temporary change in the project plans and prior to such change being implemented, GO Transit is to post such change on the current, and thereafter the enhanced, Web site, together with the anticipated duration of the change and the reasons necessitating the change; and if required, revise the project plans to reflect such change.
  2. within 14 days following the approval by the Agency of the noise and vibration monitoring methodology, commence posting on the Web site a weekly report containing the results of noise and vibration measurements as well as an assessment of the effectiveness of implemented mitigative measures; and, subject to compliance with privacy protection legislation, any complaints received, and how they were addressed and resolved."

COMMENT: Posting of complaints information is implemented and an update on the status of the noise and vibration monitoring program has been provided on January 4, 2010.

For a summary of the complete Canadian Transportation Agency Order of Specific Corrective Measures, please see the CTA website posting.