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As a war measure to save steel due to the rearmament program for Korea, the working stress of reinforcing steel was raised from 20,000 to 24, 000 pounds per square inch as listed above.

76. Design Codes and Data. - The following codes and design data were used: (1) "Recommended Practice and Standard Specifications for concrete and Reinforced Concrete," Report of the Joint Committee on Standard Specifications (1940).

(2) "Standard of Design for Concrete No. 3Yb (November 15, 1929), " U. s. Navy Department, Bureau of Yards and Docks.

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(3) "Concrete Building Design Data, Technical Memorandum No. 629, (now Engineering Monograph No. 10), U. S. Department of the Interior, Bureau of Reclamation.

(4) "Building Code Requirements for Reinforced Concrete" (ACI-318-51), American Concrete Institute.

(5) "Buildings, " Design Supplement No. 9 to Part 2 Engineering Design, Volume X, Design and Construction, (now Design Standards No. 9), U. S. Department of the Interior, Bureau of Reclamation.

(6) "Steel Construction, " American Institute of Steel Construction.

77. Structural Details. - Joints, appropriately spaced to satisfy structural and architectural requirements, were used in the structure to facilitate construction and prevent destructive or unsightly cracks. The type of joints used in the structure are 1-inch expansion joints, construction joints, contraction joints and control joints (fig. 96). The 1-inch expansion joints were formed by 1-inch corkboard and sealed against water leakage by two rubber water stops and an asphalt seal. The 1-inch expansion joint was used in the joint between the powerplant and penstock manifold anchor block, and between units 2 and 3 for the intermediate structure (figs. 100 and 101). A contraction joint was used between units 2 and 3 for the substructure joint and was sealed against water leakage by two rubber water stops and an asphalt seal. Reinforcement is not continuous across this type of joint.

Construction joints were used when it was necessary to interrupt continuous placement of concrete and to reduce the effects of restraint and temperature rise of the concrete after placement. Reinforcement was placed continuous across this type of joint to provide bond between the two placements of concrete and to insure that the concrete acts monolithically as assumed in the design. When necessary to increase shearing resistance at construction joints, the joints were keyed together. The horizontal and vertical construction joints exposed to external water pressure below elevation 5397.50 have a rubber water stop to prevent flow of water through the joints.

Control joints, types A and B, were used in the intermediate and superstructure walls. Both types have a formed groove on each face of the wall and reinforcement placed continuously across the joint. Type A has a parting strip of No. 24 gage black sheet steel along the joint with one side waxed. Type B has a construction joint key along the joint with one face of the joint painted with sealing compound. Type A was used to confine the crack to its groove. Type B was used both to confine the crack to its groove and to reduce the placement of concrete. A reinforced concrete cover slab over five-ply membrane waterproofing covered the transformer deck; the slab was sloped to drain and was provided with tooled grooves filled with elastic joint compound which were spaced at approximately 10 feet on centers maximum.

Other miscellaneous building details and a variety of miscellaneous joints and floor openings are shown on figure 96.

78. Foundation and Stability Analysis.

· The stability analysis was calculated for each section of the structure: the service bay with main units 1 and 2, and main units 3 and 4. Each section of the structure was computed separately for the first-stage

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bolts, see Detail B (55)

Type "F"rubber waterstops at constr jts

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SECTION A
FORMED DRAIN CLEANOUT

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Detail 19(416)

Formed drain

Asphalt seal & formed drain,

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RUN

4 Asphalt seal

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draft tube, Detail 17 12" To clear droin, see Detail 17

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SCHEMATIC DIAGRAM OF STEAM PIPING SYSTEMS FOR HEATING ASPHALT SEALS

SUGGESTED PROCEDURE FOR FILLING ASPHALT SEALS
After concrete is placed to elevations 5397.50 and 5396 83, flush all seal recesses by admitting water
at b7, 14 and 12 A 4-inch flushing drain is provided in run 67-17 for this purpose Fill recesses with
asphalt as follows

Admit steam at b7 When concrete is hot, pour asphalt in at b7 Asphalt flowing into runs 14-F7
and f12-17 will cool and form a plug at each side of 17, allowing run b7 17 to fill

& Admit steam of fit. When concrete is hot, pour asphalt in at f12 Filler pipe at f7 now serves as a vent pipe When no more air bubbles come out with the asphalt, tighten cap on filler pipe, allowing run F12-17 to fil

3 Repeat procedure No 2 for run 14-17

See schematic diagram

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SECTION 32

SECTIONS AND DETAILS NOT TO SCALE

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Figure 100. --Palisades Powerplant--Expansion joint details.

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Figure 101. --Palisades Powerplant--Additional expansion joint details.

substructure concrete; for the first-stage intermediate structure concrete; and for each structure completed, which included the superstructure of concrete, brick and steel framing, second-stage concrete, and installed equipment.

Since the maximum tailwater level was assumed to be elevation 5386.0 (spillway design flood), which is 11 feet 6 inches below the generator floor, and the deflection of the foundation material would be negligible, there was no problem of overturning involved. The eccentricity for all cases computed was within a few feet of the center of the base width.

The structures were designed for full uplift with the maximum tailwater at elevation 5386.0. The allowable flotation factor of safety (ratio of weight of structure to total uplift) for first-stage concrete during construction is 1. 10 and for the completed powerplant 1.25. The design results were well above these factors of safety for flotation.

The minimum allowable factor of safety against sliding for maximum loads and maximum high water surface is 1.33 and for normal loads and normal water surface is 1.75. The assumed friction of the foundation material for the andesite bedrock series is 0.70 and for the clay-silt bedrock series 0.50. Reference was made to Concrete Laboratory Report No. SP-39 and Earth Laboratory Report No. EM-286. Using these friction factors and the required loads, which included earthquake and water hammer, the sliding factor of safety was over the minimum allowable. Earth Laboratory Report No. EM286 indicated a maximum allowable bearing capacity of 8, 000 pounds per square foot. The maximum bearing pressure at the toe of the structure (critical point) was computed to be 7,500 pounds per square foot. The bearing pressure at the heel of the structure was considerably less.

79. Service Bay. - A structural frame, comprising the 1-line wall, the 2-line column, and the floors at elevations 5364. 37, 5380.00, and 5397.50, was considered fixed at the 3-line wall. The frame was designed as a monolithic, continuous structure using the method of moment distribution for the various loading conditions.

The sump floor at elevation 5346.00 was designed for full hydrostatic uplift with the maximum tailwater at elevation 5386.0. The floor at elevation 5364. 37 was also designed for full hydrostatic uplift and the sum of the moments determined from the above frame analysis.

The floor at elevation 5380.00 had to be redesigned, as the capacity of the air compressor (purchased at a later date) was doubled in size and the compressor was therefore much heavier than anticipated. The slab under the air compressor was increased from 12 inches to 18 inches and designed for vibration (see "Mechanical Vibrations," by Professor J. P. Den Hartog, second edition). In order to dampen the vibrations a 1-inch thickness of vibracork was placed between the floor slab and the concrete foundations for the air compressors.

The floor at elevation 5397.50 was designed for a uniform live load of 500 pounds per square foot except the area between the 2- and 3-lines which was designed for a uniform live load of 750 pounds per square foot. Haunches were required for the beams near the d- and e-lines and between the 2- and 3-lines, to take care of the high shear that could develop.

80. Main Units. - (a) Substructure.-- The principal design features of the main unit substructure were the bottom slab of the draft tube, the draft tube pit, and the slab under the f-line wall and penstocks. The draft tube pit was designed without the secondstage concrete in place. These slabs were designed for full hydrostatic pressure from the maximum tailwater at elevation 5386.00 for foundation reactions at the supports, and for earthquake. The rest of the substructure such as walls, draft tube piers, and the concrete over the top of the draft tube was designed for temperature and shrinkage requirements. The draft tube pier nose required a hollow, ribbed steel casting to support the load from above.

(b) Intermediate Structure.--A typical structural frame, comprising the c-line wall in b-line wall with pier, the floor at elevation 5380.00, and the transformer-transfer

deck at elevation 5397.50, was considered fixed at the substructure and analyzed for the following loading conditions: Case I, dead loads only; case II, dead load of crane; case III, live load on roof; case IV, transformer live load on transformer deck; case V, transformer live load on transfer deck; case VI, live load on floor elevation 5380.00; case VII, wind in upstream direction; case VIII, wind in downstream direction; case IX, crane thrust upstream on upstream column; case X, crane thrust upstream on downstream column; case XI, crane thrust downstream on downstream column; case XII, crane thrust downstream on upstream column; case XIII, earthquake (5 percent of dead loads plus fixed live loads applied horizontally in the upstream direction at the centerline of gravity of loads); case XIV, earthquake applied horizontally in the downstream direction at the centerline of gravity of loads; case XV, temperature rise of 40° F. for exterior members and 200 F. for interior members; temperature fall of 40° F. for exterior members and 20° F. for interior members; and case XVI, maximum tailwater level at elevation 5386.00. The frame was designed as a monolithic, continuous structure using the method of moment distribution. The moments were distributed throughout the frame for each loading condition and maximum moments and shears determined. A combination of these maximum moments and shears was used with an allowable increase of unit stresses in accordance with figure 99, and from these the cross-sectional areas of the frame members and the amount of reinforcement required were determined. The final cross-sectional areas of members, as determined by the foregoing analysis, agreed closely enough with the assumed sizes, so that a second analysis was not necessary.

The floor at elevation 5380. 00 was designed by selecting appropriate resulting moments at each end of the floor from the frame analysis. The transformer transfer deck at elevation 5397.50 (fig. 93) was changed from a beam and slab type construction to a 24-inch slab. The slab type of construction substantially reduced the shear and allowed the transformer to be located anywhere on the deck. The transformer live load was determined to be the largest load and therefore governed the design. In the design of the transformer, wheels were appropriately located on the slab to obtain the maximum moment and shears. During construction the contractor was granted permission to operate a 50-ton crawler-mounted crane on the transformer slab between the b- and c-line walls providing he met the following requirements:

(1) A 10-day minimum curing period must be allowed for all concrete before use. (2) Shoring beneath the slab must be removed so as to not transmit loads to floor elevation 5380.00.

(3) 12- by 12-inch timbers at 18-inch spacing must be placed over the slab for the crane to travel or set on. If the concrete curing period was greater than 14 days, the timber spacing could be increased to 24 inches.

The downstream part of the transformer transfer deck is supported on sloping piers cantilevered out to act as a beam. The beam was designed by a method, based on the theory of a wedge, for calculating stresses of rigid frames where the extreme fibers are not parallel. 1/

The f-line wall was designed for the superstructure frame moments taken at the base of the superstructure steel column, and dead loads, live loads, and earthquake forces. Special attention was given to the section where the wall acts as a haunched beam over the penstock opening and supports a superstructure steel column which causes torsion. Cross walls supporting the f-line wall and the downstream frame were designed by the slope deflection method. At the base of the superstructure steel column, the method based on the theory of a wedge for calculating stresses of rigid frames where the extreme fibers are not parallel, was used.

81. Second-Stage Concrete. · The design of the second-stage concrete involved mainly the design at the generator support, the floor at the rotor erection pit, and the reinforcement around the turbine spiral case. The generator is supported on six soleplates spaced 60° apart having a maximum vertical load of 125, 500 pounds per soleplate, and a maximum transient torque that would occur during accidental synchronizing out of phase of 211,200 pounds per soleplate. Analysis was made to determine the shear from 1/Olander, H. C., "A Method for Calculating Stresses in Rigid Frame Corners," a paper, Bureau of Reclamation, June 1952.

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