THESIS . An Experimental Study of Special Anchors in Sand and Clay A Theeil Submitted to The Faculty of MICHIGAN STATE COLLEGE of AGRICULWURE AND APPLIED SCIENCE by R. T . gaggeretrom Candidate for the Degree of ‘Bechelor of Science June 1947 IHESIS (Q Acknowledgement and thanks are gratefully given to Professor: 0. A. Allen and D. J. Hall for their aid, advice and cooperation in the problems involved in this paper. \ R. T. Haggeretron ”“3 F‘ F '\.r I I‘ \Hv J Up to the present time there has been very little mat- erial written upon the subject of special anchorages - or deadmen as they are commonly called. Intensive searches through the Engineering Index for the last few years netted only one article relating to the specific use of deadmen. This was in connection with anchoring of the back stays of a suspension bridge, a very special Job. The lack of any general knowledge on the subject is unfortunate because deadmen are used quite frequently in construction and erec- tion work. The most common examples of the use of deadmen are in the guying of power poles, derricks, and the afore- mentioned example of the suspension bridge. A tent peg in itself is a modified type'of a deadmen. Deadmen are also used in the holding of guard rails along the highways. If a problem involving the use of a deadman arises, the engi- neer has no books or periodicals to turn to, but must cope nith the situation either from his experience or ingenuity. He hOpes that the anchor selected will prove effective un- der the prevailing conditions. 0n the other hand, possibly, the problem defies class- ification. Each case is unique, a new problem which must be reckoned with, and variable quantities taken into ac- count. This, and the fact the deadman may assume such small significance as compared to new and different construc- tion methods, may account for the fact that there has been no attempt to report any work or experiments done on anchor- ages. The object, then, of this thesis is to test in the labor- atory several types of deadmen under varying conditions, with the purpose of noting actions and reactions and attempting to interpret and analyze the results as observed. It being be- yond the scope of the author, no attempt is being made to derive any mathematical formulas as the existence of so many variables involved, and the time factor, make the effort prohibitive. At the present time, the Michigan State High- way Department is having research work done on this phase and also the experimental phase. The author, however, is working independently on the project. The two main points being investigated are-the depth of burial of the deadman and the angle that the tie line, makes with the vertical. By varying these conditions and attempting to keep several other variable conditions con- stant, it is expected and hOped that some favorable results will be obtained. It is expected to bury a large deadman and pull it out later in the spring and the data from the laboratory models and the large scale deadman to be correla- ted, if possible. The two mediums selected for pulling out of the deadman were sand and clay, these being chosen because they are the most extreme conditions an engineer is likely to encounter. The sand, a Miami sandy loam was almost perfectly dry, hav- ing been in the warm laboratory for about three months and frequently stirred and mixed up. A series of tests was run on the dry sand, the sand was moistened, samples taken from ‘ three different places in the box and the average moisture content of the sand computed. Tests were run on the wet sand, after which the sand was removed. The clay, a brown Miami clay loam, was substituted and the tests continued in this medium. The means of testing the-deadman - practically this consisted of pulling them out of the sand or clay - is shown in fig. 1. It consists of a piece of cast iron pipe, 30 inches long and 3/fi of an inch in diameter, to which the deadman are guyed. This pipe was fitted with a plug in the lower end which had a 1/4 inch hole in it for pinning to a pair of 1/16 x 1 x l x 3 inch angles which supported the pipe on a wooden bracket securely fastened to an inside corner of the box. Theoretically there is a little friction between the plug and the pin, but after oiling the connec- tion, it was considered to be negligible. The pipe is free to move in a vertical plane only, tralerse motion being eliminated due to the design. Holes were drilled in the pipe at different places for the attachment of hooks to which the deadman and pulling line were fastened. An angle 1/8 x 1} x it x 8 inches was riveted with two pieces 3/32 x l x 6 inches to which a 2} inch pulley was pinned with a 1 inch pin. Again this was oiled and friction between pin and pulley was considered negligible. The line for connecting the deadman to the pole, and pole across the pulley to the load was of the clothesline variety averaging .132 inches in diameter. The friction be- tween the pulley and the line is assumed to be .3,lbecause 1 Analytical lechanics for Engineers, Seely a Anson, John Wiley d Sons, New York, pp. 123 . e . '\ w.s\“‘~e s ." " s. a 0‘ ~§ \. Q.‘Q‘mt§ .- .g-....- C (/72! («/AV SOS/EMA 77C ORA W/Né’ OF APP/4 R34 703. §§U§Y KO \<.w§ WN