00715549

Component

http://onlinepubs.trb.org...trr/1995/1504/1504-012.pdf

https://scholar.google.co...ield&publication_year=1995

To access forest products, streams typically need to be crossed by heavy equipment. In many cases, the access is only needed for a short time. The cost and time involved to construct a permanent crossing exceeds the need. Also, permanent access into the area is unwanted, making it necessary to remove the crossing that closes the road. Removal may cause pollution to the stream and continuous erosion problems, especially when culverts are used. A possible solution would be portable, temporary, reusable crossings made of readily available, inexpensive materials. The U.S. Department of Agriculture Forest Service has investigated this type of crossing option. Several products were considered as potential crossings. Five crossings were chosen for field trials: pipe mats, gratings, Terra Mats, wood pallets, and wood mats. All five crossings work well, although each has different strong and weak points. Most of the work has been performed in Florida. Conditions in other states will require different design modifications and improvements. Although quantitative information is still being analyzed, qualitatively the crossings greatly reduce impact to weak soils of stream beds. This impact was observed to be lower particularly when compared with using no crossing or removing a permanent crossing.

This paper appears in Transportation Research Record No. 1504, Modeling and Model Verification; Testing Pavement Layers and Materials; and Low-Cost Drainage Structures. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved

01399829

English

p. 118-124

1995

Transportation Research Record

0309061725

Figures (1) ; Photos (7) ; References (4) ; Tables (1)

Bridges; Causeways; Grates; Pallets; Performance; Portable equipment; Soils; Streambeds; Streams; Temporary structures; Tires

Bridges and other structures; Design; Geotechnology; Highways; Terminals and Facilities; Vehicles and Equipment; I24: Design of Bridges and Retaining Walls

TRIS, TRB

Jan 2 1996 12:00AM

• CENTRIFUGAL MODELING OF LEAKING UNDERGROUND STORAGE TANKS
• DETERMINATION OF DEPTH TO BEDROCK FROM FALLING WEIGHT DEFLECTOMETER TEST DATA
• DETERMINATION OF RESILIENT MODULUS OF SUBGRADES USING BENDER ELEMENTS
• ESTIMATING PERMEABILITY OF ASPHALT-TREATED BASES
• METHODOLOGY FOR FUNCTIONAL DESIGN OF LOW-LEVEL RIVER CROSSINGS IN SOUTH AFRICA
• MODELING FLOWSLIDES CAUSED BY STATIC LOADING
• MODELING THE STABILITY OF SAND FOUNDATIONS DURING EARTHQUAKES
• RESILIENT PROPERTIES OF LABORATORY COMPACTED SUBGRADE SOILS
• RESPONSE OF PAVEMENT SYSTEMS TO DYNAMIC LOADS IMPOSED BY NONDESTRUCTIVE TESTS
• SHEETPILE CELL FILLING: FINITE ELEMENT MODEL VERIFICATION FOR TWO CASE HISTORIES
• TESTING AND MODELING OF TWO ROCKFALL BARRIERS