PHASES III & IV TRENCH BLASTING FOR SANITARY SEWER INSTALLATION - - PowerPoint PPT Presentation

DC 02 & DC 03 SANITARY RELIEF PROJECT (BRENTWOOD BLVD – CONWAY ROAD) PHASES III & IV

TRENCH BLASTING FOR SANITARY SEWER INSTALLATION

Agenda

• Introductions
• Goals
• MSD’s Mission and Project Overview
• J.H. Berra Const. Co., Inc.
• Important Names to Mention
• Project Description & Proposed Blasting Areas
• Rock Excavation
• Vibration and Vibration Monitoring
• Pre-Blast Surveys & Damage Claims
• Feedback and Questions

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GOALS

• Demonstrate to the City of Ladue officials the benefits of blasting
• vs. mechanically breaking the rock on this project
• Receive “Zoning Approval Letter” from City of Ladue to allow

blasting per St. Louis Country Regulations in order to maximize efficiency and minimize disturbance

• Explain the requirements set forth by the Contract regarding

blasting

• Answer questions from City of Ladue regarding blasting

procedures and regulations

MSD’s MISSION

• “To protect the public’s health, safety, and water

environment by responsibly providing wastewater and storm water management.”

PROJECT CLEAR

Improve water quality in streams Investment of billions of dollars Required by US EPA and Missouri Coalition for the Environment. www.ProjectClearSTL.org

DC-02 & DC-03 SANITARY RELIEF PROJECT OVERVIEW

• During heavy rains, the current sanitary sewer system can

release sewage into creeks

• Project Goal is to eliminate seven SSO by December 31, 2023
• New larger diameter sewer from Brentwood & Manchester to

Conway & Lindbergh. Excess flow will be stored in tunnel.

• Phase I in Brentwood is complete. Phase II in Rock Hill and

Ladue is under construction. Phase III & IV will begin soon.

J.H. Berra Construction Co., Inc.

• Formed 1963
• Successfully completed construction of

DC 02 & DC 03 Sanitary Relief Phase 1

• Employ approximately 150 employees
• Employ (3) three Missouri Licensed Blasters

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Other Key Players

• Vibra-Tech
• Pre-Construction / Pre-Blast Surveys
• Vibration Monitoring / Blast Specialist
• Austin Powder
• Blasting Consultants
• Supplier of Blasting Agents
• St. Louis County – Mike Burkemper
• Regulatory Agency for Blasting Operations

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Project Description – Blasting

• Includes approximately 7500 Lineal Feet of Trench

Blasting (Total Project = ~ 18,000 LF)

• Pre-Blast Surveys within 1000’ Radius of Any Planned

Blast Location

• Storage of Blasting Materials in accordance with St.

Louis County

• Blasting Operations in accordance with OSHA

(Occupational Safety and Health Administration) and MSHA (Mine Safety and Health Administration)

• Average Depth of Rock = 10’
• Average Depth of Sewer = 22’

Deer Creek Trunk Sewer

Why we are here? Rock Excavation

• Blasting v. Mechanically Breaking
• Breaking– Hoe Ram
• Loud
• Continuous
• Slow – 10 feet a day
• Blasting
• Less Noise
• Less Disruption
• Quicker – 40 feet a day

Schedule Impacts

• 7500 LF OF PROPOSED TRENCH BLASTING
• BLASTING = APPROXIMATELY 200 DAYS TO COMPLETE
• BREAKING = APPROXIMATEY 800 DAYS TO COMPLETE
• BREAKING THE ROCK IN THESE AREAS CAN TAKE

NEARLY 4X AS LONG AS BLASTING

• IN PERSPECTIVE, IF A HOMEOWNER’S PROPERTY IS

200 LF LONG/WIDE, THE WORK WILL TAKE NEARLY 1 MONTH VERSUS 1 WEEK TO COMPLETE

Proposed Blasting Areas

• Phase II upstream to Overbrook Drive
• Litzsinger Road to Log Cabin Lane
• City of Ladue Property Along S. Outer 40
• Note:
• There are specific areas along this alignment that will

required mechanical means of rock excavation (i.e. Close proximity to houses, utilities, roadways, etc.)

Two Methods of Drilling & Blasting

• Option #1:
• Drill through the overburden (Dirt) and blast rock prior to

any excavation taking place

• Option #2:
• Strip overburden (Dirt), drill rock, load holes, cover, then

blast. Note: Option #1 is the preferred method; however, the condition of the overburden will determine if it is feasible

OPTION #1

Preparing to Blast

After Blast

Rock Excavation

Construction Complete

OPTION #2

Strip Overburden (Dirt), Drill, Load, Cover, Blast, Excavate, Install

Example Blasting Videos

Video #1 – without pre-excavation Video #2 – with dirt backfill (Most Applicable to our Proposed Blasts) Video #3 – with blasting mats

So How Will MSD Protect Homes?

• Notification before work begins
• MSD CM team will monitor the contractors

procedures

• Adhere to Missouri Department of Public

Safety and St. Louis County Blasting Requirements

• Contractor Responsible for:
• Secure / Safe Site
• Homes Pre-inspected
• Vibrations Monitored
• Vibration Data Available as Requested

Structures from USBM RI-8507

Older Plaster-

• n-Lath Interiors

2 Story Wood Frame 1 Story Wood Frame 2 Story Brick

FACTORS AFFECTING STRUCTURES

PEAK PARTICLE VELOCITY FREQUENCY AIR OVERPRESSURE

1 10 100

FREQUENCY (Hz)

0.1 1 10

PARTICLE VELOCITY, in/sec

. 3 i n 0.75 in/sec Drywall 0.50 in/sec Plaster . 8 i n 2.0 in/sec

USBM – SAFE LEVELS OF BLASTING VIBRATIONS FOR HOUSES

10.00

3.00 0.75 0.50 0.02

0.00 2.00 4.00 6.00 8.00 10.00

Reinforced Concrete Mortar Joints Drywall Plaster on Lath Initial Perception

Vibration Standards

(2 to 10 Hz) (3 to 15 Hz)

Remote Seismograph Monitoring Stations

Portable Seismographs

Air Overpressure Effects

Air Overpressure Level Comparisons

0.05 0.1 0.15 0.2 0.25 0.3 P.S.I.

Thunder 1/2 mile State Limit Thunder 1000' Single Pane Glass Breakage

124 dBL 133 dBL 138 dBL 160 dBL

Saint Louis County Blasting Requirements

Offer Pre-Blast Inspections Within 500’ Radius Ground Vibration Limit 2.0 ips Air Overpressure Limit 133 dBL

Pre-Blast Inspection

Method of documentation may include digital photographs, video, audio description, photo log or diagrams

• f interior conditions

and defects performed room by room, wall by wall Exterior conditions and defects are documented with digital photographs and/or video, including a photo mosaic

Property Owner Claims

• Contact J.H. Berra Construction Co., Inc.
• Kevin Bielicki – Project Manager
• John O’Connor – Risk Manager
• MSD Construction Management Team
• J.H. Berra will reach out to the homeowner and will set up a

meeting to survey the damaged areas

• If necessary, a Post-Construction Survey will be offered to

the homeowner for comparison

• J.H. Berra will turn the claim over to its insurance agency

which whom will perform the investigation and be in touch with the property owner

• It is required by MSD to document all claims as they occur

and the status of all claims is closely monitored by the CM Team

Feedback & Next Steps

• Our Goals
• Demonstrate to the City of Ladue officials the benefits of blasting
• vs. mechanically breaking the rock on this project
• Receive “Zoning Approval Letter” from City of Ladue to allow

blasting per St. Louis Country Regulations in order to maximize efficiency and minimize disturbance

• Questions and Discussion

Thank you!

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J.H. Berra Project Manager: Kevin Bielicki (314) 487-5617 Kbielicki@jhberra.com