Trench Safety Summit - Colorado

Trench Safety Summit - ColoradoPresented by the North American Excavation Shoring Association (NAXSA) and OSHA in partnership with:

Associated General Contractors (AGC) of Colorado

Colorado Contractors Association

HBA of Metro Denver (Colorado Association of Homebuilders)

Colorado Chapter of the National Utility Contractors Association (NUCA)

Colorado 811

Unsafe work in trenching and excavation

industry is becoming an epidemic.

• Trench Fatalities A total of 488 trench and

excavation deaths between 1992 and 2000,

an average of 54 fatalities each year.

• Trench Fatalities for each calendar year 2014

and 2015. 11-Nationwide.

• Trench Fatalities for calendar year 2016

23-Nationwide.

• 15-Nationwide in the first 7 months and

estimated to surpass 30 fatalities in 2017.

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Trench collapse fatalities have more than

doubled in 2016.

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Who’s dying in trench “accidents”?

• Sixty-eight percent of trench fatalities

occurred in companies with fewer

than 50 workers.

• Over 43% of fatalities where

construction laborers.

• Hispanic workers die with 1 in 3

deaths occurring in construction.

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Who’s dying in trench “accidents”?

Fatalities by age:

• 36% 29 years old or less

• 26% 30-40 years old

• 38% 40-years old or older

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What protective system used?

•76% nothing was used

•12% Sloping and

Benching

•8% Trench Shields

•4% Shoring6

Where are we dying?

•72% less than 9’deep.

•19% 10’-14’ deep

•6% 15-19’ deep

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BRIEF DESCRIPTION OF ACCIDENT

• February 6, 2015-Manhattan, KS.

• A 30-year old City of Manhattan employee was working in a 5’ deep trench fixing a water main break when a trench collapse occurred. The work was buried to his waist for 20-min. when he was rescued by two local fire departments.

• He was transported to a local hospital where he was pronounced dead after succumbing to his injuries.

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Key Elements of OSHA Excavation Std.

• Designate a competent person to conduct daily inspections of excavation, adjacent area, and protective systems, and take appropriate measures to protect workers.

• Use adequate protective systems-shoring, trench shields, sloping or benching.

• Develop, implement, and enforce a comprehensive written safety program for all workers that includes training in hazard recognition.

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Key Elements of OSHA Excavation Std.

• Ensure that spoil pile and heavy equipment are kept away from edge of the trench or excavation if workers must be present in the trench.

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Adequate means of egress from

trench excavations.

• Excavations 4’ or greater

• Ladder, stairway or ramp

• No more than 25’ of lateral travel

• Ladder must be three feet above top of excavation

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Exposure to vehicular traffic.

• Employees exposed to public

vehicular traffic shall be provided

with, and shall wear, warning

vests or other suitable garments

marked with or made of reflect

ionized or high-visibility material.

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Excavation Standard Fed. OSHA

1926.652 (a)

Employees shall be protected from cave-

ins by an appropriate protective system.

What is the exception to this?

Exception: If excavation are

made of entirely in stable rock

or are less than 5 ft. deep, and

a competent person has

determined that there is no

potential for a cave-in.

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Registered Professional Engineer….

• Means a person who is registered professional engineer in the state where the work is to be performed. However, a registered professional engineer, registered in any state is deemed to be a “registered professional engineer” within the meaning of this standard when approving designs for manufactured systems for “manufactured protective systems” or “tabulated data” to be used in interstate commerce.**

** Only 1 out of 49 states requires a 2nd engineer's stamp from an in state engineer on manufacture’s tabulated data.

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Question: Can

Manufacture’s Tabulated

Data supersede the

tables found in the

OSHA Standard?

Answer: Manufacture’s Tabulated Data that

exceed the limitations of the various tables

found in tables found in Appendices B thru D

of the excavation standard (29 CFR

1926.650) may be developed and used in

the design and application of trench systems

provided the development and use are

approved by a registered engineer.

Source: OSHA Letter of Interpretation October 1, 1991 (Letter #1991_10_01)

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1926.652 Requirements of Protective

Systems

• Shields shall be installed in a

manner to restrict lateral or other

hazardous movement of the

shield in the event of a sudden

lateral load.

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What is the

acceptablegap

between a

shield and

the dirt

walls?

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OSHA does not give a distance

between the dirt walls and your

trench shield.

You would need to refer to the

manufacture’s tabulated data sheet

for this distance.

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Can I use Speed Shore Trench

shields in combination with a

sloping system when the total

depth of the trench is greater than

twenty (20) feet deep?

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Example: A trench total depth will be 36’

deep and the contractor is going to stack 3-

8’ high trench shields with a rated capacity

that meets the depth requirements for the

trench shields location in the trench based

on the Competent Persons soil

classification.

The top of the trench will be sloped 18”

below the top shield based on the OSHA

sloping and benching tables.

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Based on Speed Shores Technical

Data Sheet # SS-6899-2 Dated

06/08/99.

This is acceptable as long as all other

provisions of Speed Shore’s

Manufactures Data is applied.

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Simple Slope excavations 20 feet

or less in depth

shall have a

maximum allowable

slope of 1 : 1 or 45

degree in B soils.

B=Dx2+W

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Simple Slope

excavations 20

feet or less in

depth shall

have a

maximum

allowable slope

of 1 : 1 1/2 or

34 degree in C

soils.

C=D x C + W 25

Aluminum Hydraulic Shores

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What is the minimum number

of Hydraulic Shores that can

be spaced horizontally?

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Trick question!

Who’s engineering

are you using,

OSHA or the

Manufacture’s

Tabulated Data?

It’s not one!

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Hydraulic Manhole Whaler System

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Hydraulic Manhole Braces with Sheet Pile

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Modular Aluminum Panel Shields

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Steel Trench Shield with High

Clearance Arches

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Slide Rail with Guide Frame

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Shot Crete

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Sheet Pile with I-Beam Wales and I-Beam

Cross Braces

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I-Beam with Wood Lagging, Sheet Pile,

Hydraulic Wales and Cross Bracing- Site

Specific Engineered System

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Beam & Plate with 80-Ton Struts

What’s wrong with this picture???

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What’s wrong with this picture???

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It’s up to you to work safe!

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Questions

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