timber pedestrian bridge inspection report

May, 2020

Timber Pedestrian Bridge

Inspection Report

Timber Pedestrian Bridge over Fitchie Creek ERA Project #W20073.00

Prepared for: Catatoga Property Owners Association (CPOA)

mlange

Image


Inspection Report

Engineering Resource Associates, Inc. (ERA) 1 May 2020

TABLE OF CONTENTS

1.0 INTRODUCTION ...................................................................................................................................... 2

2.0 FIELD OBSERVATIONS .......................................................................................................................... 2

3.0 RECOMMENDATION .............................................................................................................................. 2

4.0 PERMITTING REQUIREMENTS AND FEES ............................................................................................ 3

APPENDIX A …………………………………………………………………………….... LOCATION MAP

APPENDIX B …………………………………………………………………………….... PHOTOGRAPHS


Inspection Report


1.0 INTRODUCTION

The Catatoga Property Owners Association (CPOA) contracted Engineering Resource Associates, Inc.

(ERA) to inspect a timber pedestrian structure that crosses over Fitchie Creek. The subdivision bridge is

located between the streets of Arrowmaker Pass and Pars Path in unincorporated Elgin. The timber

structure is approximately 24’-0” in length and 6’-9” clear deck width. Engineering Resource Associates,

Inc. inspected the bridge May 4th, 2020.

2.0 FIELD OBSERVATIONS

Timber Planks. The timber planks are in poor condition (Rating 4). Majority of the planks are rotted and

split. Many planks are also loose (See Photograph 9).

Timber Railings. The timber railings are in poor condition (Rating 4). Railing has vertical splits. Its loose

in some areas and has algae growing on it (See Photograph 5).

Timber Power Poles. These power poles are used as the main load carrying system for the pedestrian

structure and spans over the creek to the embankments on each side. The power poles are in poor

condition (Rating 4). There is extensive decay, cracking and splitting in these members. These members

have up to 30% section loss (See Photograph 6,7 and 8).

Timber Abutments. The abutments are in serious condition (Rating 3) (See Photographs 7, 8, and 10).

The bearing transverse member that supports the longitudinal power poles is completely deteriorated.

There is severe decay with more than 50% section loss (See Photograph 10). Additionally, the

embankment on the east abutment is continuing to erode and water is getting behind the abutment.

Embankments. The creek is cutting deeper and deeper into the embankments (See Photographs 3 and

4). Concrete blocks were installed at the east abutment to redirect the water away from the abutment.

Ratings are based on the Illinois Highway Information System Structure Information (ISIS) Manual.

Highest rating for timber superstructure is an 8 (Very Good) and the lowest is a 2 (Critical). See attached

sheet for descriptions for each rating.

3.0 RECOMMENDATION

The structure should be replaced within to 2 to 3 years with a new structure that is longer to span over

the east side embankment erosion. A sign should be added to warn pedestrians to “proceed with

caution”. Additionally, new boards should be placed longitudinally over the deck to prevent punctures

through the deck.


Inspection Report


A prefabricated timber structure will cost $115/sf (material only) to replace. Typical cost for construction

would be 1.5 times the material cost ($175/sf for material and erection). It would be recommended to

replace it with a structure at least 34-ft in length and a clear bridge width of 6’-ft for a construction cost

of $35,700.

4.0 PERMITTING REQUIREMENTS AND FEES

This bridge is in the Floodway governed by IDNR-OWR Part 3708 rules. Doesn't matter if it is a small

bridge or owned by the HOA, it is required to follow the State's law regarding hydraulic structures in the

floodway. A permit submittal will be required for both Kane County and IDNR-OWR for any changes made

to the bridge besides maintenance. A full bridge replacement will require a full permit submittal. Repairs

that do not change the dimensions of the structure will not require a permit submittal.

Permitting Fees

INDR-OWR ~ $3,300

Kane County’s fees for review ~ $7,000

Kane-DuPage Soil and Water Conservation District ~ $1500 + $500 reimbursable

US Army Corps -$0

I would budget 120% of the fees listed above which comes out to a total of ~$15,000.

Engineering Fees

Hydraulic Modeling = $6,000

Floodplain & Floodway Permitting (INDR-OWR, Kane) = $7,000

Structural General Plan & Elevation drawing (1 sheet) = $3,000

Total Engineering = $16,000

ILLINOIS HIGHWAY INFORMATION SYSTEMStructure Information and Procedure Manual

Item Name SUPERSTRUCTURE CONDITIONItem No. 59

Sheet 9 of 9

CONDITION RATING GUIDES FOR SPECIFIC SUPERSTRUCTURE MATERIALS

TIMBER SUPERSTRUCTURE

Code _________________________Description___________________________________

8 VERY GOOD. May have only very minor defects in beams or stringers at non-critical locations.

7 GOOD. Minor insignificant decay, cracking, or splitting of beams or stringers.

6 SATISFACTORY. Some decay, cracking, or splitting of beams or stringers may be occurring near the main load carrying portions. Fire damage limited to surface scorching with no significant section loss.

5 FAIR. Moderate decay up to 10%, cracking, or splitting of beams or stringers but no significant effect in critical areas such as beam ends and mid-span. Fire damage limited to surface charring with minor section loss up to10%.

4 POOR. Extensive decay, cracking, splitting or crushing of beams or stringers, or fire damage with main load carrying portions affected. Section loss up to 30%.

3 SERIOUS. Severe decay, cracking, splitting or crushing of beams or stringers, or fire damage with major section loss up to 50% in critical load carrying portions of members. A further progression of problems noted for a condition rating of “4”.

2 CRITICAL. Beam ends may be crushed or split with settlement of deck. Any further deterioration of problems noted for a condition rating of “3”. Section loss over 50%, special feature inspection is required to allow bridge to remain open. The Bureau of Bridges and Structures shall be notified immediately.

NOTE: For codes N, 9, 1 and 0 condition rating guides pertaining to all superstructure material types, refer to Item 59 (Sheet 2 of 9).

Timber Pedestrian Bridge Inspection

Appendix A – Location Map

Engineering Resource Associates, Inc. A-1 May 2020

Pedestrian Bridge over Fitchie Creek


Appendix B - Photographs

Engineering Resource Associates, Inc. B-1 May 2020

Photograph 1 –Top of Deck; majority of the planks are rotted and split.

Photograph 2 – Top of Deck; majority of the planks are rotted and split.




Photograph 3 – Flint Creek; looking upstream

Photograph 4 – Flint Creek; looking downstream




Photograph 5 – Bottom Railing board deteriorated at railing

Photograph 6 – South Longitudinal Timber pole has longitudinal cracks at midspan of structure




Photograph 7 – North longitudinal timber pole has longitudinal cracks at bearing;

abutment is not supported

Photograph 8 – East Abutment; water is eroding the banks and abutment




Photograph 9 – South longitudinal timber pole (beneath deck) has longitudinal crack with

significant section loss

Photograph 10 – Bearing log no longer exists

timber pedestrian bridge inspection report

Documents