The Knowledge Bank at The Ohio State University

Ohio State Engineer

Title: Righting a Million Bushel Elevator

Creators: Remington, Franklin

Issue Date: May-1923

Publisher: Ohio State University, College of Engineering

Citation: Ohio State Engineer, vol. 6, no. 4 (May/June, 1923), 9-10, 12.

URI: http://hdl.handle.net/1811/34207

Appears in Collections: Ohio State Engineer: Volume 6, no. 4 (May-June, 1923)

THE OHIO STATE ENGINEER

Righting a Million Bushel ElevatorBY FRANKLIN REMINGTON,

Chairman of Board of The Foundation Company, New York CityArticle and photographs by courtesy of The Tech. En-rineerinp: News, publication at Massachusetts Tech.

^S^IHERE are few engineering undertakingsy^J that are more spectacular and appeal5555 more to the imagination than the rightingEs*^ of the Transcona Elevator.

About ten years ago, the Canadian PacificRailway, to facilitate the speedy shipment ofgrain from the Canadian Northwest, built aone-million-bushel grain elevator near Winni-peg. It was of reinforced concrete and con-sisted principally of a workhouse seventy feetby ninety-six feet and one hundred eighty feethigh and a bin house seventy-seven feet by onehundred ninety-five feet and one hundred twofeet high. The latter was made up of sixty-five circular bins fourteen feet four inches in

should safely carry a load of from three tofour tons per square foot. The ultimate load-ing of the clay under the mat was calculatedfor this structure to be three and three-tenthstons per square foot. It was therefore assumed,after a slight initial settlement, there would beno difficulty.

The Canadian Pacific Railway began storinggrain in the Transcona Elevator in September,1913. Care was taken to fill the bins so thatthe load would be uniformly distributed. OnOctober 18, with 875,000 bushels in the bins,settlement was first noted and a vertical sett-ling of one foot took place within an hour.Within twenty-four hours, the bins had leaned

GRAIN ELEVATOR UPSET BY DEFECTIVE FOUNDATION

diameter. These and the diamond-shapedspaces between afforded the storage capacityof approximately one million bushels. Boththe workhouse and the bin house were equippedwith the most modern conveying machinery forrapidly loading and unloading cars.

The whole structure—workhouse and binhouse—rested on a floating foundation of rein-forced concrete. The supporting mat for theworkhouse was fifteen feet below the prairielevel. For the bin house it was twelve feetbelow at which elevation the soil was foundto be firm gray clay extending to a depth ofabout forty feet. In supporting the elevatoron a floating foundation, the customary prac-tice of that part of Canada was followed. Soil

to the west twenty-seven degrees. The lowertests were made and it was found that the clayside was twenty-nine feet below its originalposition and the higher about five feet aboveits original position. Only the upheaval andcompacting of the soil on the west side pre-vented the complete overturning of the struc-ture, which in fact was found to be in a mosthazardous position with its center of gravitydangerously near the lower edge.

The railway engineers, confronted with anunprecedented problem, appealed to the lead-ing firms specializing in engineering construc-tion requesting that schemes and estimates forsaving the grain elevator be presented withoutdelay. The rivalry to produce a practicable

10 THE OHIO STATE ENGINEER

plan was keen and finally the Canadian Pacificadopted the scheme of The Foundation Com-pany as being not only the most practicable,but also the most novel. It included some fea-tures which might be characterized as daringbut it also promised economy.

Among the first steps taken by the CanadianPacific after the failure of the elevator was toget the grain out. This was done in three weeksby tapping the bins through the sides. Conveyorsbrought from Chicago assisted in the operationand when the contractor began work he foundan empty structure weighing twenty thousandtons. Strangely the bin house was not materi-ally damaged by the rough treatment it hadreceived. This is one of the most striking evi-dences on record of the strength and practica-bility of reinforced concrete. The cover photo

the construction company were therefore con-centrated at first on this tall narrow concretestructure. The columns must be underpinnedto rock. On account of the height of the struc-ture, its small base and the heavy loads, it wasnecessary to shore the building before startingoperations under the columns. For this purposetwenty small piers were sunk to rock around theoutside of the workhouse. These afforded asure footing for shores to each outside column.The next step was to sink piers to rock directlyunder each of the twenty-four columns. Gen-erally, the Chicago well method was followedin the construction of the new foundations.Wells five feet in diameter were used. The un-derpinning operations were carried on wjthgreat care, and extraordinary devices such as atwo hundred eighty-pound plumb bob suspend-

RIGHTING THE ELEVATCRNote the difficulty of sinking pier to rock under each of the tvvenly-four columns.

shows how the elevator looked in December,1913, when the Foundation Company startedwork. An investigation of subsurface condi-tions showed that the clay which had beenfound to be stiff at the elevation of the rein-forced concrete supporting mat, was very softbetween elevation —30 and —40. The dis-placement of this soft stratum was apparentlythe cause of the failure. A line of bouldersunder the east side of the bin house explainedthe tipping to the west. Rock was found to beabout fifty-five feet below the prairie level.

The scheme adopted for salving the struc-ture involved not only righting the bin housebut the sinking of piers to rock for the supportof the workhouse and the bin house.

The railway engineers decided that the un-certain condition of the workhouse demandedthat it be given first attention. The efforts of

ed from a height of one hundred sixty feet wereadopted to detect undesirable movements. Inspite of the treacherous subsoil conditions andthe hazards involved, the underpinning of theworkhouse which had been begun in December,1913, was completed without mishap in June,1914.

In February 1914, the Foundation Companywas ordered to proceed with the straighteningof the bin house and thus the most spectacularpart of the work was begun. The emptystructure weighed twenty thousand tons andthe problem was to right it and underpin it torock. For the sake of economy, it was de-cided not to raise the structure to its originalelevation but merely to rotate it into a verticalposition around the west or low edge. This

(Continued on page 12)

12 T II K O II I O S T A T l<] V] N (i I N V) V) \i

(Continued from page 1 0 )would leave the mat in its final position atabout thirty-eight feet below the prairie level.

Figure 1 shows the elements of the schemeto right the bin house. First piers were sunkto rock under the low edge. These were toafford a support for the fulcrum on which thestructure was to be rotated and later to becomepart of the permanent foundations. Rightingmotion was produced by weakening the core ofearth under the high side and by a line of push-ers along the west side. The sinking of wellsfor piers was greatly complicated by waterwhich flowed into most of them at the rate ofover one thousand gallons per minute. Thewhole undertaking was made difficult by thecongestion under the structure where the workhad to be carried on. The contractor was con-stantly called upon to resort to special devices.When the fourteen piers under the low sidewere Hearing completion, work on the remain-ing fifty-six piers was started and wTas contin-ued during the straightening process. Wellsfor piers were of the Chicago type seven feetin diameter. While work was in progress, therailway engineers decided that it would be de-sirable to have the mat of the structure rightedabove the ground water level instead of belowas it would be at —38. To accomplish thisend, the structure was rotated on the fulcrumunder the west side through about ten degrees.Then the fulcrum was changed to the next rowof piers and the structure rotated through abouteight degrees. In this manner, the fulcrumwas shifted three times and the bin house actu-ally lifted more than twelve feet. Today inits vertical position it is about fourteen feetbelow its original position. It was not raisedto its original level because it satisfactorilyserves its purpose as it is.

(P lan to right tlie b in-house.)

The task of righting the bin house wasstarted about March, 1914. It was completedOctober 17—within two days of the estimatedtime. As in the case of the workhouse, pre-cautions were necessary throughout the opera-tion* and it was completed without mishap.Measurments to detect movement or danger-ous stresses in the structure were taken twicedaily. The success of the undertaking de-pended absolutely upon the fidelity of theengineers.