a le i os es e: ne — THESIS UU an) ELL alae ew LL STANLEY R. HILL 1920 TON mA nN ea 1293 00991 2605 ~ ~HESIS K {| 454 PLACE IN RETURN BOX to remove this checkout from your record. TO AVOID FINES return on or before date due. MAY BE RECALLED with earlier due date if requested. DATE DUE DATE DUE DATE DUE a PLACE IN RETURN BOX to remove this checkout from your record. TO AVOID FINES return on or before date due. MAY BE RECALLED with earlier due date if requested. 4 DATE DUE DATE DUE DATE DUE 1996 = ~c/CIRC/DateOus.p65-p. 14 — =—- —— — 5 Tne Design end Construction of = Retaining Jall. A Thesis Subvmitted to Tne Faculty of SICHIGAN AGRICULTURLL COLLGS. 3Stenley BR. Hill queen, Ca andidate ror tne degree of Sacnelor of science. Pavruary, 1920. The Completed Wall. 401417 Thesis lL9ZO. Bivliozreapny. Books:- American hicnweay dnerineers nendboox, Arthur 3lanchard, author. American Civil snzineers Focxet Book, .ensfield lierriman, editor. lecnanical itngineers nandbook, ion larxs, editor. t-4 risnway snzineers Handbook, Harger and B0:ney, editors. Concrete snzineers Handbook, Hool and Johnson, editors. Structural sn-ineers Handbook, Ketchum, editor. A Treatise on tasonry Construction. Baker, editor. T.0.>5. Civil Anszineers Handooox, I.5.-5. ungineers, editors. -27azZines:-~ Professional iiemoirs, Vol.2@ and Vol.i, army snzineers,iasuinston Barraci:s,editors. Tnesis 1920. The present sutomotive aze demends good roads, in Spite or tovocr:rs,hical ba:riers or otuer obstacles. Cn the Yedersl Aid Project ;3 in 3araga County, vetween tne villeses of L'Anse and Baraga, tre proposed road ran alony tne snore of Le te Sucvarior and te State Hisnvay Departme:t was compelled to master the following situation. ine original road at the point mentioned was very narrow, due to tne over-hanzins cliff on one side and a steep drop to the la‘-e on the otrer. To widen tne road was essentizl and the only possible way to do it ves to mare a fill out in the laxe and place the road on the top. The only railroad running to the Copper Countr: of lichissn, has its ricnt of way direct- ly on the top of the cliff so it wes out of tne questivn to con- sider removing an: of the cliff, or tne Red HXocts, ::s it is commonly exlled. A fill into tre lake necessitated some pro- tection from tne action of the waves. The expense of building a sea well froin the lea*xe bed to the top of the fill Was pro- nibitive ani to build s smaller wall would allow any sea that micvnt come uv, to coupletely go over it and wash away the fill, Woich would have to be made of sand. After much study and various surveys it wes decided to build a low retainin= wall out in tine laze and to protect the fill by a rip-rap of blue granite slabs that are auite vlentiful in the vicinity. A ver: accurate survey was made of the location, and “ne nature of the sub-soil anéc the bearins gualification of the bed rock was determined. The laxe bottom alonz= tne procosed Wall wes tested by means of drills. The dril!s were driven every ten feet and driven down far enoush to determine tne exact depth . coe PTS ee ee TS Roar me hei Oi 2 ie Ne te eS P ier a he airs +) Re a CROSSECTION OF ROAD before + ofter placing of wall, ee - ET : wig Ve PTR cree cd etin leae ieee Pare ae eae ee . ‘ lal Toe egend, fedolod sd ri Clay gravel Ss Origirial AT oa gts) mrs Ne ee rad ta om a | @ C? re 0 ae, ee) OQ @ ww) e BY to solid roc. All souwndinzs were recorded and then volotted S Snown on plate I. Crossecticns were also made and the fete as came plotted szowinzs both tne road crossection before and after the proposed wall is in. Flate II. snows this crossection and zives some idea of tne nature of the soil. After all tne vorelininary surveys had been made and the plan view oy the wall decided upon it was tnen necessary to design the wall to withstand the action of the waves, nold uo the fill o- sand and beheevy enousn to counteract the action of frost and freezing temperature. Trere are two seneral types of retainin: walls, tnose that are made of plain concrete and those of reinforced concrete. The plain concrete walls depend on their weisht for stability While the reinforced walls depend upon a series of -.ever arms for stavility. For 2. wall to meet tne three requirements enu- merated I tnersfore decided would have to oe of piain concrete, neavy enourn to sitnustand tne liftins action of tne frost and Site a batter on tae out-ide to counteract the action of the waves, Tne ordinary theoretical formulas are of but little value in designing retainins walls. The problem presents sucn condi- tions that cennot all ve expressed in an algebraic for ula. Something had to be assumed and it wes much more simple to assume the thiclmess of the wall at once than to derive it from equations based upon a number of uncertain assumptions. The first assump- tion made was tnerefore the thickness. The American vivil snsi- neers Handbook recommends for desienins retaining wells to be built in a country where the frost penetrates more than three STABILITY OF THE RETAINING WALL. fe i Ak Tan Ndi Ae 8.5 Width % base 5.0 ed “ op ae) Wesght of section of wall 7f' FhAICk = 29.75 150 St aye Ltrepose =Lsurchorge = 33.5° werght & fill = ae “ en Nl k Ll-i k7o tal ae ee ae tS ee LL fat, a) -—/"= 2° i) -Y i Mnesis Fase 3. feet in the ground, a top widtn of not less thin two feet. The width of the base depending upon tne work the wall is to perform. ith a heavy s.rcharge such as this wall is to hold the avproximate formula is x (b * .60 xh)(Paze 599 1043) Tho maximum (h) is found to be 8.5 feet and through out the rest of the design the maxinum heignt will be used. Assuming the width of the top to be two feet and the maximum height as 8.5 feet the value of (b) will be .60 x 8.5 = 5.1 Using 5 feet. Several empirical rules have been devised by prominent envineers but the majority of them prove out about the same as the one used from !ierriman. The most used formulas are those of General Fanshawe, Sir Benjamine Baker and Trautwine. After the proposed section had been decided upon the next most important question in the design coneerned tne probable prezsures to be exerted by the retained material and many theories have been advanced on the suvject. Nearly es many theories have been advanced as there have been walls ouilt but the ones generally accepted and solutions based on are those of Rankine and Coulomb. Both men lead to identical eauations for determining the pressures existi.g: in non-cohesive cartns, Ranzine's formula was used in the general désicn for de- termining the pressures exerted. To fully determine the pressure of the filling on a retaining wall it is necessary that the resultant »ressure be known (a) in amount, (b) in line of action, and (ce) in point of application. In referring to Plate iio.3 the graphical solution for the line of action anil the point of avplication of the pressures is found. “7 | e ‘3 ~ LNHesis reve 4, In referring to the figure tne outline of the wall is shown by the lines (a b ec ad); the line (ck) representine the surface or the surcharge or the slope of tne bacx filling, which on the average is 15 horizontal to 1 vertical. The top of the filling cominz to the top of the wall. In makin? calculations, only 1 foot of the lenzthn of the wall and of the back filling is taken; thus, it is simply necessary to take the area of the section of the wall and the bac‘rins. The material composing the backing is assumed to oe a fairly loose sand: sravel witn @ possibility of it be- comin? saturated citner from excess rain or drenched from waves washing over tne wall. ~ It is generally assumed that tne maxinum pressuve on a retaining wall is caused by a vedge-snaped prism of earth (bck) included between the wall and the line (bz), which bisects the ancle (cbi), or tne anzle formed by the rear face of the wall and the slope of revose of the fill. This line is called the line of maximum pressure and the prism whose crossection is (cbk) is calle< the prism of maximum pressures. The point of avplication of the pressure P was found by determining the center of gravity (e'g') of the triansle (beck) and drawing the line (c'e) parallel to the lino of ximum pressure. The intersection (e) of this line with the back of the wall is the required point of apvlication of (P). The superimposed load that mictht oceur on the top of the fill was not considered, due to the nature of the orivinal crossection ani because of tne Slictht difference * .is load would make. Tne maximum load tnat could pass over a nisnway would not be greater than a road roller Thesis Pare 5, or some sucn piece of road machinery. Rankine's theory assumed that the pressure is alwars parallel to tne earth slope; but tnis does not Seem reasonable Since the direction of tne pressure snould be the Sane es that of the motion of tne sand. axperinents have snown tnat the surcharse hes little or no effect u:on the lateral pressure and that the direction of the pressure is parecllel to the slope of repose. The equation for fin ving the value of (EF) when the ancle of surcharze and the slope of repose are the same is (P > *. wxh” cosO), where (w) is the weight of the filling in counis per cubic foot, (h) the depth of the wall in feet, (0) is the anzle of repose of the fillins and (2) the resultant pressure on tne wall in pounds. The resultant pres:.ure will be at an ancle of 33° - 40'. Solving the equation P = 24135 x Ovex .545 = P = 2657.97. The veicnt of the wall is found by the equation Y = } @-+ bd xX hxw where (w) is the weight of a cubic foot of ée 4 ryt concrete found in the table on pase 153 ACSEB to be 150-4 ver cubic foot, (a) is the width of the top and (b) is the width of the base, h being the altitude. Solvin~ the equation for a section 1 foot tnicx i + 24 5 x 8.5 x 150. W 4462.5). The direction the weiztnt (w) is on the vertical line through the center of sravity (CZ) of the wall seetion,the total pressure (2), actin= on the base of tne wall is then the esultant of the pressure (P) and tne weisnt (J) of tne wall. Tnesis -s28%@ Oe Its marnitude and line o% action are determined by the parallel>~~an (oe'rv), in which (oe' =P) and ov! =i), the voint (o) boinst the intersection of the line of action af (P) with ea vertical throucth the center of tnis will ve e::plained later. As a rule, it is customar; to assume that the only load upon the base of tne wall is the weignt of the masonry, and also to assume that tne center of pressure is to be kept witn- in the middle third of tne base, and that consecuently the maximum pressure is not more than twice tne mean. Computed in this way there is no likelihood that the masonry of an ordinary retainin= wall will fail by crushing. Little or no attention is therefore viven in the desizn of a retainins wall to tne factor of safety asainst crushin?s. After tne wall had been proved safe from overturning, Sliding ani crusning the next thinz to design was the joint to be placed at the end of a days pour. In any kind of a joint tre only force to act on it would oe tne force of pressure in tne .irection already described, and it would act in shear. Concrete of a 1:3:5 mix has a shearing strensth of 1180 lbs. per s:.in.e «its Sucn a hizth Shearing strensth any joint tnat would extend the total heisht of the wall would have sufficient strenzth. The joint chosen is 6" wide running the full depth of tne wall and projecting about 4" into the next section. This design was changed slizthtly while on the actual construction in order to make the removing of tne forms more convenient. The completed desien was sent to the State iignvway Depart- wz. Pipe A: Ser fer Conmcrere “ ; 3 Fs is @° ae Lal | i? 8 ~ ‘ a J i _ 8 ; pirch 4-70. oy e- Vy y 4 an OB re tae pour 5 oe MEY EYPANSION JOIVT To be placed at end of days Ce Liev top of (= Sy | J eae ? pers 6 = PAS fae, Ww, fount at = “Ss wy Ss / EY Cy oo Ny 3 if Shi A: g a Milo MER As Te td ee tet vsed Ye IP deh 1) Le A ed os4eur € atl a rid ctr ae J STANDARD SECTION Thesis Farce 8. ment for anproval where snecifiecations were dra.n up ani tne contract let. @ne contract wes avarded to "The with spares Construct ‘on vOuveny! OF cournton, Licnigan, and the price nemed was ./14.00 a cuvic yard of concrete, the State to prevare tne foundation for tne wall. Tne follovins extracts were taxen from the specifica- tions prepared for tne concrete wall. naterials. verment - The c2mant sna 1 be Fortland and shall meet the requirements of the State hivh.a:y Department. Concrete Agcregate - Tne fine at :resate shall consist oz stamp sand opvteined from the Isle Royal Jtamp mill and the larse av=sregate shall all paxvs throuzn a screen with 2] ineh mesh. Tne large azzregate to be obtained to aN from the Champion Sand and Gravel Sompany and shall con- cist of pit run crushed to pass throuvh a 2, sereen but to ve retcined on a + screen. Sumber = The lumber for tne for.s sneall have a tnickness of l inch, snall be matcned and finished on one side. “ne studding to be made of 2x 6 material. axcavation- Tne exc vation snall all ve done by the State but tne contractor shall see tnat tne foundation is cleared of all loose gravel and tnat the concrete is voured on a solid foundation. Concrete- The concrete snall be macnine mixed and of such cotAsistency thet it will flow into the forns with- out tne separation of the coarse aszresate from the mortar. A411 concrete shall be deposited in horizontal ~ARal TC nesis rave 9. layers and shall ve comvacted by tanpinz with a strai-x~ht shovel until tne surplus water has risen to the surface. orss - Forms snall be substantial and unyieliin= and — taf ouilt co tna* tne conerete will conform to tne design ani ilconsictns, ani so constructed trat tnere will be no lealkaze of sortar but have gates provided for the fa) escave OL ce) tne water thet will rise to the top. The forms are not to be renoved vitnin 56 hours of t:.e time of pouring. Proportioning- For portion of tne wall from the water level to the foundation, one (1) part of cement, two (2) parts stamp sand, and four (4) varts of large artregate. For tne portion from the water line to tne top of tne wall, one(1) part of cement, tnree (3) parts ro stenp sand and six (6) parts of larse aszregate. _ The firm of Smith and Sparks sub-let tre dvuilding of tne wall to a concrete construction com any of ilenominee,:.icnigan. Tho price named being “11.00 a cubic yard, Smith and Spzurks to suvcly all necessery evuipment 2nd handle the buying of the materi-1 for them. The difference of 3.00 veinz esti- metrod acs t.e vilue of devreciction on the 24uipment loaned (9 tne verlson Convany. Durinz the wransling over contract letting and sub- letting, two rod men and myself staxed out tne well pre- paratory to tne evecavation. Tne instrument was first set up at tne snore end 53 feet to tne left of stetion 780 - 59.2 ani 2. temporery line run parallel to the center line of the road, wooden stales being driven y driving the rods with a hoavy mallet tne wedse,restinz on tne bed rocx, world force the solit end apart and the rod would become firzsly held in the rock. Tne rods were made of mild steel 14 inches in diameter ani 3 f:et lsns. The followin’ photo snows tne metaod in wnicn the rods were placed and tne conditions tne en worxed under. Thesis Pase 14. After the first. week the work of excavating and plac- inz of the tie rods just kept ahead of the construction company but at no time during the making of the wall were the forms setters hindered by lack of space in which to place the forms. During high winds it was necessary to keep a man with the form setters to clean out what dirt “ould wash in the trench. The breakwater helped cousider- ably in protecting the excavation from the action of moderate waves but whenever a storm arose the low breakwater was of little value. Fhoto lWo.5 shows how just a licht wind made the waves come in, and several times the wind was strong enoush to drive the water as high as the road level. Thesis Yage 15. During the week that the excavation work was begun the construction company vad arrived on the job with their ecuipment and had set up their camp, which consisted of a sleepine tent, cook shanty, stables and cement shed. The first work tzey did toward the actual construction of the wall was to build the forms. The lumber used for these forms was of pine ceiling six inches wide and ten feet long. Ten sets, consisting of a front face, rear face and necessary braces, were made before any forms were set in place. Wnile the carpenters were naxing the forms it was necessary to be constantly on the job to see that they were made accord- ing to specifications. The slightest variation in the di- mension of an inside brace,altnough seemingly small, would make a sreat deal o- differance in the amount of concrete tne forms would hold. eee — oe mg : a x r Fd P. PP ol A + te N thd A ee ee a CAwTe \ 4 — re TAT tea We of form setup ‘2... ri ~~ 9g oy rd p. S NM : pe. 5 u A ee 5, vi ; ; : _ “5 Ps rr man p ‘ik ¢ Biff prece an iy " ne : hy ee Ped a aed eR S IR nw] o F< a head Sand bege l / y arr iS a a Re A P - ri HK! es | eA x - iin; Aa pz eee NALLY, De i fe ie pls See Aas ihe iN AN \ “4g Salli Wale Z Am - —/ WI\ WWNZ LM = mS ZA 7). Ee a 1 ait a rr oe + —+4- ae eS Mae -+- I x a 6 In settinz up tne forzs care was toren to nave the rear face pernaniicular. T.e insid?2 braces wer: then nailed on .n” the outside face put in place. Tne form for the rear ws oraced firaly to the shore by m2ans of a two by Sour bracing. The front form was held in place by twist- ing wire from the studdinz on the front face to the studd- ins on tne reaz face. Tne wires were vwlaced eivnteen inches apart alon~ tne lensth of tne stuiding ani twisted tignt enough t) resist tne weignt of tne wet cocrete. After the foris had been firnly wired tozgetner ceient oerzs full of S:-nd were placed alon: the base on the outside to prevent any leakace of mortcr wrile tne forms weve deinz filled. ‘The weicht of te send also hel-ced resist tne lifting action of fne water on tne forms. Tre followin= pnrtos snox clearly how the forms were wD t uv ard nov tne bracing was accomplished. tne studs were 'd + n ae aced t.o feet vrart anid tne braces used to nold tne sections apart were o two by four lunber. Page 17. Thesis Page 18. i. As soon as enouvn Sor2s were in place the contractor would estimate the «mount of concrete the: could pour in the days run and the end board would be put in accordingly. This end board not only served to keep the concrete from running out of the forms but it also was built to carry the form for the expansion joint, as shown on the plates. Before any conerete wes allowe2d to enter the forns it was necessary to measure up the volume of concrete it would hold. To do this I took cross sections every five feet alon- the length of the forms my rodman holdins the rod at tnree different points at the five foot section. The average height was in this way determined and the average area determined for each CONSTRUCTION OATA SHEET. Oe 2 a a a ee ee WI, PIPE eo ae F i Ped 52.9 24.0 /00 ie Aug 6 6.82 24.8 ier) 2F. 4- 106 VA md Ar i w] RT Rea) a] a ee =] Pump or wprhing i A Ere) CRAY ee PX] Cd al mL Mo sand | ERE a) 26.8 5/.8 vA) Paw rr aI Mee) lad iad 3 eT Maa 8.0 27.F 62.0 63.0 232 VA Lk ee 1s nT are forcls Aug 16 ol ae) 60.4 62.2 aes ve Or mL) Setting | forms Aug 19 et ee oe Aug 20 oa] 27.8 ee a) 27/ 7 re sia 29.2 cal = §2.0 rare i Aug 22 Setting | forms Aer 8.3 PsA) ee) 4 Ir 10.5 re rd Setting | forrs eo oi oe) 62.0 a ek) a Aug 27 8.4 29.2 eae -2 56.5 Pe 7 eo) nd Vt =) F235 F2.0 aw] 7 Totals 664.5 671.2 26/7 101.5 ieee Rg A. Fdcl/ aati oe Thesis Page 19. section. Plate iio.8 shows tne azount of concrete “soured during each day's work and also shows the amount of cement and wrought iron pipe used. The notes for the cross section- ing are to be found in +=emppmummtim the back of this book. To place the concrete in the forms the mixer was placed on the road avove and the concrete conveyed by troughs to the forms. ‘The pump for forcing the water up to the mixer was laced on the snore of the laxe and a one inch pipe laid along the road to a voint avout a thousand feet from the mixer where a section of pipe about twenty feet in lenzth was raised into the air. To get water taps were provided along the pipe at convenierit places. The odject of tne raised pipe was ‘o sive tne mixer a uniform pressure and the lensth of nive acting as a reservoir. The materials for mixing were arranged around the mixer as shown in the following photo. -nesis Page 20. The next photo shows the relative position of tre mixer forms and puzp when at work. The ansle of the chute changes for each location of tne mixer. “hesis Page 21. a ed 6 at pe 1. 30. Oe OD. Oo 10 bundles fori wire #9 e OO Various xinds of nails i.iscellaneous expenses LOO sallons sasoline © £0 9396.80 10.00 100.00 20.00 32 /ft e round “0300 5i/tt. 660 feet Lis 200 Te ° O05 Sis 10 LOS. 30 100.00 7755260 deducting office expenses W an da Profit for sud-contractor not Lo6l.2cl 2nesis 1:a7e 26-6 4 xc oJnien the State 21d took 50 Jars «and the exmense outside of the snvineerinz is as follows: Snovelers ~ .:5.00 per day “48.00 rill men “ 350 15.00 8 2 1 foam and driver 9.00 | 2.00 l Zoreman 8.00 8.00 1 Inspector and timeiee per 4.00 4.60 Total expense per day 82000 Totel expense for tne 30 days work ry 30 x 82.50 = 32475.00 Zne hi. cost of excavating was due to the fact that the men hei to work :t all times in water up to their arm nite. Yho itn wage paid the men vas necessary in order ' 1 47 . _. i* * 7 4 =: 1.2 ~~ oo . 4. *. ws * s 50 Hesd Gnen on the jod ani workins under tne conditions mentionet. Enzineer. The The Contractor Thesis Passe 27. In sunnarizing, the problem is divided into three . parts; the design, the construction, and the cost of con- struction. The wall could have been much more economically de- sicned if exact data as to the nature of the fill dirt had been obtained. At the time that the design wes made no definite filler had been chosen but there was a possibility of either having a fill of beach sand or one of a wet clay azceregate. The design was made o. the assuzption that the filler with the greatest horizontal component, beach sand, would be used, and so the wall is over safe from the over- turning and crushing forees of the fill. The force of the frost can only be assumed and it remains to be seen just what the action of an extremely cold winter will have on it. The present winter has seen the temperature at 40° below zero, much lower than has ever been previously noted in that territory. The foundation for the wall is, I believe, plenty low enough to be very little affected by the frost. The only criticism that can be offered in regard to the construction is the inadequate machinery used. #ith a larger mixer and a more effective means of obtaining water the work could have been completed much sooner, and in a better manner. Delays caused by the lack of sand were due entirely to the neclisence of the foreman. Orders for the stamp sand used were Thesis Paze 28. required to be in at least three days in advance and near the end of the job the foreman attempted to make what little there was on hand last the rest of the job. It is practically impossible to compare the cost of the wall with anything else that the State Highway has built. At no time previous have they built anything that compares with it either in design or the cnnditions under which it was con- structed. The price of 314.00 per yard seems like a very reasonable price for concrete work put in under the prevailing conditions ani although the work was put in just after the war I do not think that the pre-war prices would have been much less. The cost of constructing concrete highways in the vicinity is about 312.50 per cubic yard and this does not in- clude any reinforcements or drainage. The fact that the wall had to be poured under water and that the mix was of two different proportions easily licenses the difference between the prices for roads and of that for the wall. s { A] ae we : . . - : : - ' ‘ & I, sae ore) 610.83 S70) Pe a) 50 ot) i218) sts) a = ee ay ye ¥ Aug 25 pt : 7 a 7 4 * he as ; wi es feb eta) oS fk tee eer qu 43a 5 eat aaa aes oe oe, ee ee ee ry eta eae ae a a» 5G ea es oO. kK j~ ea fo} ba} 2 = ce - uv a] ep io Is ops i 39 oi fe 2a ae al! we j a ° ~ . 5 HK t Or | on me MOR OO - ale, . 13 ed yi ai ~ oq che fo et eee es nd Sey of ee t 5 ae eed Ol it Oi ry a) ee er m tals cofoe oF 5 3 ior . J re) es . z i * as . CYywo 4h is o 2) 5 a f) ool ts! Favaean! pa) C aos w Ce. paw :) epsts BO Ay tA Mot” «ge Pe o ot 7 i: ee Wi ~~ mS ae ae eee ee ene eee ae : pt tien 4 ed cos OO Cf 9fo ft tho who i : x oe eee ee ey Pi act Mh eae oe) ~ nN foo ad re | “a ee oe ee = ee’ Wee = Ge 3 re re ca co od he) « o ed ei — &; . | ed a ° . 1 as avd Cc re ct - o% a, ij a be Pete 5 7 od LS Pe Y o “ Oi a } t ae L mere & ac! ot —*. ™ De @ =) 4 a Ds) a rie oO ar = sid of \e