« PreviousContinue »
REPORT OF COMMITTEE I-ON ROADWAY
J. R. W. AMBROSE, Chairman;
C. M. McVay, Vice-Chairman;
To the American Railway Engineering Association:
As instructed by the Board of Direction, your Committee has condensed its report as much as possible. Sub-Committees were named to report on the various subjects assigned and their reports will follow; information relating to the activities of the Committee during the past year has been given in the various Bulletins.
ACTION RECOMMENDED 1. That the definitions of terms under Revision of Manual (Appendix A) be approved for insertion in the Manual.
2. That report on shrinkage and swell of grading material (Appendix B) be received as information.
3. That the conclusions in reference to methods employed and results secured in the treatment of sliding cuts and fills and soft spots in excavation and embankments (Appendix D) be approved and inserted in the Manual.
4. That report on effect of heavier power and increased tonnage upon roadbed previously considered stabilized (Appendix D) be received as information.
5. That report on filling of bridge openings (Appendix E) be received as information.
6. That the conclusions in report on “Ditching" (Appendix F) be approved and inserted in the Manual.
7. That report on chemical killing of weeds (Appendix G) be received as information.
8. That report on design and use of reinforced concrete culvert pipe (Appendix H) be received as information.
9. That report on excessive cost of maintenance during the early period of operation (Appendix I) be received as information.
10. That the suggested outline of work (Appendix J) be referred to the Board Committee on Outline of Work.
Recommended Outline of Work for the Ensuing Year Your Committee recommends the following subjects for the coming year's work:
1. Study the Manual and submit revisions thereof, particularly the grading specifications.
2. Study and report on the economics of bridge filling.
3. Study and report on the effect of heavier power and increased tonnage upon roadbed previously considered stabilized.
4. Study and report on chemical killing of weeds.
5. Study and report on excess costs of maintenance during the early period of operation.
6. Report on the use of corrugated metal culverts in railway work and prepare specifications for material and workmanship.
THE COMMITTEE ON ROADWAY,
J. R. W. AMBROSE, Chairman.
(1) Revision of Manual Your Committee recommends the following definitions for the Manual:
Casting (verb).-Disposing of excavated material by a single operation (2) SHRINKAGE AND SWELL OF GRADING MATERIAL C. M. McVAY, Chairman;
either by hand or machinery. Station Men (noun).-Men engaged in station work. STATION WORK (noun).-A small piece of grading work extending over
one or more stations.
W. H. WOODBURY, E. J. BAYER,
F. M. GRAHAM, H. W. BROWN,
Sub-Committee. Considerable correspondence has been carried on by the Sub-Committee and additional information requested from various sources, but very little has been received that would add to what has already been reported.
On account of the varying formations throughout the country and the different methods of handling them in doing work, the results are difficult of comparison.
Taking the eastern portion of the country for example, we have successively starting on the north, the granite formation, then the socalled gravel formation, part of which would be classed by some engineers as loose rock, then through the limestone areas and following this the sandstone and clay and then the loam and sand. All of these formations have many varieties and ramifications and each give different results when used as grading material.
All embankments on our railroads today. are made from material from three sources, namely the cuts or excavations necessary on the line, borrow pits adjacent to or near the line, and industrial waste given to the railways for disposal. Many embankments are a combination of material from all three sources, and while it is difficult to get definite information on the relative yardage in cut and fill for material from the first two sources, it is impossible to get anything on the third.
The Committee believes it is possible to obtain the necessary data to make a comprehensive study of this subject if the members will cooperate with them, and with this end in view we submit herewith a form with the request that members in doing new work, have the information collected as outlined, particular attention being given to question No. 6, for this point has been the Committee's greatest difficulty.
FORM FOR REPORTING GRADING WORK
(c) Depth of cut below surface. 3. Material in embankment.
1 year later.
6 years later.
4. Method of excavating.
(a) Capacity of steam shovel dipper.
If by teams or grading machines.
(e) Average length of haul.
(a) Height of trestle.
If by teams.
(d) Thickness of layers. 6. If any additional filling material was put on the embankment during settling period, so state, showing material and yardage.
7. Weather during work. 8. General information.
Some interesting information has been received from the Southern Pacific on the subject of shrink and swell. This Company made an investigation of eight railway embankments on a line, the building of which was discontinued in 1912 and work has not been resumed. Track was not laid on these embankments, therefore the shrinkage of the material was entirely natural and not augmented by trains passing over them.
The results obtained would probably be different had the fills been subjected to the compressing action of trains. An analysis of the results of the investigation shows that in every case other material than common earth was encountered in the excavation and placed in the fills. Each embankment had rock in some form.
The fill containing the greatest percentage of earth shows the greatest shrinkage and those with the greatest percentage of rock show the greatest swell. In the eight cases about 15 per cent of the material was common earth, 65 per cent. was cemented material, 14 per cent trap rock and the balance more or less of a solid formation.
Cross-sections were available for this work as of 1912 both as to material removed from excavation and material placed in embankment, and it was found that in six of the eight embankments the calculations showed an increase of some 6.61 per cent. to 21.34 per cent; the two remaining examples show a decrease or shrinkage of 5.67 per cent. and 9.83 per cent. The eight fills taken together show a swell of 7.768 per cent. above that measured in excavation.
In 1920 the fills were again carefully cross-sectioned and the results show that in four of the eight cases there was a swell ranging from 0.997 per cent. to 17.24 per cent., and the four remaining cases a shrink of from 1.27 per cent. to 17.34 per cent. Taking an average of the eight fills a shrinkage of 0.362 per cent. is shown.
Information has not been secured as to the method of filling used in making the fills. As mentioned in previous reports of this Committee, fills made with teams and scrapers are generally compacted much more