Jeffrey Lew, Dulcy Abraham, Reini Wirahadikusumah, Javier Irizarry, Carlos Arboleda PURDUE UNIVERSITY CIB W099 Conference University of Hong Kong May 8, 2002 Excavation and Trenching Safety: Existing Standards and Challenges

The Need 100 fatalities per year in trenching and excavation accidents (Hinze and Bren 1996) Most deaths in trenches are from cave-ins

Mail survey conducted by Equipment World (1998): 41% of all respondents said they experienced a trench collapse on one of their jobs Of these, 76.5 % said that the trench collapse was due to unstable soil, 29.4% human error, 11.8% insufficient shoring/shielding The Need (cont.)

Role of the competent person Thorough knowledge of excavation safety standards including soil classification. Capable of identifying existing and predictable and hazards and unsafe conditions. Knowledgeable in the proper use of protective systems and trench safety equipment. Designated to have the authority to stop work when unsafe conditions exist.

Unsafe trenching operations Protection in excavations ?? Loose rock/soil !!! Means of egress ??

Unsafe trenching operations Job site analysis Existing Utilities Existing Utilities Water Loose rock/soil

Causes of trench-related fatalities (NIOSH ) BLS CodeDescriptionOccurrences Freq.% 041Excavation or trenching cave-in Caught in or compressed by equipment or objects Contact with underground, buried power lines Fall from ground level to lower level Caught in or crushed in collapsing material 36

Occupational fatalities caused by excavation or trenching (U.S. Department of Labor, Bureau of Labor Statistics) Total: Construction General building Heavy construction 1 Heavy construction 2 Water-utilities Heavy construction Special trade contractors Plumbing - heating Miscellaneous Excavation work : Except buildings2 : Except Highways3: Not classified

Analysis of data from NIOSH Occurrence of accidents – by month ( )

Analysis of data from NIOSH Occurrence of accidents – by age of workers ( )

Occurrence of accidents by SIC code SIC Standard Industrial Classification 1623 : Heavy construction-(Water, sewer, pipeline, communications and power) 1794 : Excavation work 1611 : Highway and street construction 4911 : Electric services 4923 : Natural gas transmission and distribution Others : Others categories with 1 case NA : Not Available

Most frequently cited trenching related standards ( ) Rank Description of standard Standard# Cited$ Penalty 1 General requirements for all types of scaffolding ,971,165 2 Fall protection scope/applications/definitions ,770,419 3 Excavations, general requirements ,479,795 4 Ladders ,310 5 Construction, general safety & health provisions ,617

Most frequently cited excavation violations ( ) Rank29 CFR 1926.___Description of standard 1.652(a)(1)Protection in excavations 2.651(k)(1)Daily inspections of excavations 3.651(j)(2)Loose rock/soil 4.651(c)(2)Means of egress 5.651(d)Vehicular traffic

Occurrence of accidents – based on time of day NIOSH ( ) Data Available: 30 out of 52

Occurrence of accidents – based on occupation NIOSH ( ) Occupation

OSHA recommendations – based on accident reports

50 Accidents Month of Event: Oct. 15%, Apr 12% Outcome: 65% fatal, only 35% non- fatal Classification: 40% water, sewer, pipeline workers or SIC Code Union status: 98 % non-union

50 Accidents Trench Characteristics: Depth 0-20 feet 37% 0-5 feet 89% less than 15 feet

Conclusions 1. Lack of competent person 2. Lack of training