Figure 179.-Powerplant expansion joint details-Unit bays 1 through 8.

NOTE

For general notes and reference drawings see 557-D-729

-30

DEVISED WED ELEVATIONS TO AGREE WITH
M.D.B. FALLOUT PROTECTION CHARGES.

REVISED VOP ELEVATION OF WED BETWEEN
D.D. UNITS AND S

D.

18-19400

a

3-11-99

ADDED ELEVATIONS FOR TOP OF EXPANSION JOINTS
BETWEEN UNITS.

ASTUSER UNIT REVIRCO C-LINK ELEVATION AT
WATAY DIENSTVAR

REVISED EXP STS ADJACENT TO
TREATMENT STRUCTURE.

ADDED UP TO EL 3007.30

SEWAGE

UNITED STATES

DEPARTMENT OF THE INTERIOR

BUREAU OF RECLAMATION

COLORADO RIVER STORAGE PROJECT

MIDDLE RIVER DIV. OLEN CANYON UNIT-ARIZONA-UTAN

GLEN CANYON POWER PLANT BAYS I THRU 8

UNIT

EXPANSION JOINT DETAILS

Figure 180.-Powerplant expansion joint details-Unit bay 8, machine shop bay, and service bay. (Sheet 1 of 2.)

Figure 180.--Powerplant expansion joint details-Unit bay 8, machine shop bay, and service bay. (Sheet 2 of 2.)

effects of restraint and temperature rise of the concrete after placing. For an example of the sequence of concrete placement and location of construction joints in the powerplant, see figures 181 and 182. The reinforcement is continuous across the construction joints and care was taken to obtain good bond between adjacent placements of concrete. The joints were keyed when it was necessary to develop additional shearing resistance and to assure monolithic action of the structure. Rubber waterstops were used in the vertical construction joints and noncorrodible metal seals were used in the horizontal construction joints, where necessary, to prevent the flow of water through the joints.

(3) Contraction joints are used to relieve tensile stresses induced in a concrete structure by shrinkage. These joints are commonly used where temperature variations are small and the volume change in concrete is confined to shrinkage. Contraction joints differ from construction joints in that the reinforcement is discontinuous at the joint and means are used to prevent bond between the joint faces. A contraction joint may also serve as a construction joint.

In the power plant, contraction joints were used in the mass concrete beneath the main unit bays, the machine shop bay, and the service bay. They were also used in the substructure concrete of the main units from the mass concrete up to elevation 3124.75. The machine shop bay and the downstream training wall were separated by a contraction joint at the m-line wall from the rock foundation to the top of the training wall.

(4) Control joints were used in the superstructure walls and the cable and elevator tower to prevent or control unsightly cracking. Two types of control joints were used, type A control joints and type B control joints. For the type A control joint, the continuity of the concrete surface is interrupted by interior and exterior grooves and a parting strip of sheet metal is placed in the joint. The reinforcement is continuous across the joint. The parting strip forms a weakened plane and induces the wall to crack at the grooves. When the control joint is continued past a floor, a floor blockout is used to prevent the floor from cracking. The floor blockout is filled after the initial shrinkage and cracking has taken place.

The type B control joint is a vertical keyed construction joint with grooves on the interior and exterior face of the wall. The first placement of

concrete is painted with sealing compound to prevent bond and relieve the stress in the wall. The interior and exterior surface grooves are similar to the type A control joint grooves.

(k) Second-Stage Concrete.-The volume of second-stage concrete in each unit bay was 3,750 cubic yards. The contractor chose to use prepacked concrete around the upper and lower draft tube liners and up to the centerline of the spiral case and penstock at elevation 3140.00. He used regular cast-in-place concrete above elevation 3140.00 to the top of the generator floor at elevation 3168.50. The total volume of second-stage concrete used in the powerplant was 30,000 cubic yards.

The spiral case was designed to resist the difference between the pressure under water-hammer conditions and the spiral case installation pressure. To determine the required reinforcement around the spiral case, the embedded penstock, and the outside face of the concrete at the galleries and passageways, an analysis for a pipe shell with a cracked section was used. By inspection, the points of points of minimum second-stage concrete thickness were found and the necessary reinforcement determined for these areas. Each case was then analyzed as a hollow cylinder with many cracks in the concrete to a depth equal to the distance of the hoop reinforcement from the inner face and subject to uniform pressure on the inner and outer surfaces.

Each generator is supported on 12 stator foundation caps. The vertical load on the six foundation caps under the bearing bracket arms was 360,000 pounds per cap, and the vertical load on the six alternate foundation caps was 40,000 pounds per cap. The tangential force due to the single-phase short-circuit torque was approximately 220,000 pounds per cap. The concrete foundation was designed to withstand the maximum synchronizing out-of-phase torque of 6,150,000 foot-pounds per foundation cap, which is equivalent to 388,400 pounds of tangential force per cap. The bearing and shearing stresses on the concrete under the foundation caps were checked and found to be within the allowable limits. Stresses in the anchor bolts and soleplates were also checked and found to be within the allowable limits.

(1) Surfacing.-The following types of floor surfacing or finishes were used in the powerplant, dam adits, and dam elevator towers:

(1) A 6-inch concrete surfacing with reinforcement was used on the elevator machinery