ML19329E157

App 2G of AR Nuclear 1 PSAR, Stability of Soil Slopes. Includes Revisions 1-18

ML19329E157
Person / Time
Site:	Arkansas Nuclear
Issue date:	11/24/1967
From:	ARKANSAS POWER & LIGHT CO.
To:
References
NUDOCS 8005300761
Download: ML19329E157 (7)

Text

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x AFFEliDIX 20 STABILITY OF SOIL SLOFES OF THE COOLING WATER INTAKE AND DISCFJd1GE CANALS, AND '0F THE DIERGEIICY COOLIIIG WATER POND 2.G.1 INTRODUCTION 2.G.2 DESIGN CRI G IA 2.G.3 SOIL DESIGN DATA 2.G.4 STABILITY RIALYSES 2.G.5 RESULTS OF MIALYSES k

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F 2.G STABILITY OF SOIL SLOPES OF THE C00LIUG WATER IUTAKE AHD DISCWJ1GE CANALS AIID OF THE EMERGENCY COOLING WATER POND 2.G.1 INTRODUCTION The intake and discharge canals will be excavated in soil and bedrock, and the emergency cooling water pond will be excavated in soil only. Typical sections of these structures, together with the evitical slip circles corresponding to a seismic loading of 0.2g ground aceleration, are shown on the attached Figure 2.G.1. The overburden soilu are stiff clays which will be excavated to slopes which will be stable under normal operating conditions, under seismic loading, and under rapid drawdown. The analyses

s. 3w that soil slopes of 1 5 to 1 will be adequately stable under all of these conditions of loading.

. The assumptions made, the procedures used, the design criteria, and the results of the analyses are given below.

2.G 2 DESIGH CRITERIA The canal and cooling water pond slopes are designed with a minimum factor of safety of 15 for all normal operating conditions. For unusual con-ditions which may occur rarely, if at all, a factor of safety of 1.1 was i considered acceptable. These unusual conditions included rapid drawdown of the water level in the cooling water pond or in the cana.1, and also an earthquake loading considered to be a steady horizontal force due to an acceleration of 0.2g. Rapid drawdewr and earthquakt loading conditions were not considered to occur at the same time.

2.G.3 SOIL DESIGH DATA The necessary design parameters for the stability analyses were based on data obtained from undisturbed samples of the overburden soils whicP were tested in the laboratory. The data used are tabulated below:

Unit weight of soil above groundwater table - 124 lb/cu.ft .

Submerged unit weight of soil -

61lb/cu.fc.

Consolidated drained shear strength is:

s = 400 + ptan 22 Where s is the shear strength in pounds per square foot p is'the normal pressure on the plane on which the shear strength is being measured.

2.G -2 03 3*

Attached Figure 2.G.2 shows the results of the laboratory shear strength tests and the relationshi,' of the design strength envelope to them.

The groundwater table was assumed to be ccnstant at El.338 in the over-burden for the canal slope design and constant at El. 347 in the cooling water pond analysis.

2.G.4 STABILITY ANALYSES The analyses were made in accordance with the modified Swedish Slip Circle method of analysis known as the " Method of Slices" . The procedure is described in the Corps of Engineers Manual for Civil Works Construction EM 1110-2-1902 entitled, " Soil Mechanics Design - Stability of Slepes and Foundations". It is assumed that the water and earth pressures on the sides of eacn slice are in balance. The seismic load is applied as a horizontal static load equal to 0.2 times the total weight of the sliding mass for an acceleration of 0.2g under maximum earthquake loading.

To facilitate the work, the analyses were progrc=ned for the computer. The program was derived in Fortran IV for the GE 625 computer from one developed-in 1962 by the US Army Corps of Engineers, for use on an IEM 1620 computer.

2.G.5 RESULTS OF AUALYSES The results of the stability analyses are given en the attached Table I.

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TABLE I.

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INTAKE AND DISCHARGE CANALS-

Structure Excavation Slope Minimum Computed Loading Condition Factor of Safety Intake Canal 1

1 5 to 1 Normal

' Discharge Canal 27 1 5 to 1 ' "

Norma 1 Intake Canal 1.8

'1 5 to 1 Seismic (0.2g) g  : Discharge Canal 15 b

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1 5 to 1 Seismic (0.2g)

. Intake Canal 1.2 4:- 1 5 to 1 Rapid Drawdown Discharge Canal 1.7 1 5 to 1

.- Rapid Drawdown-17,

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EMERGENCY COOLING WATER POND 1.5 to 1 Normal 33 1.5 to 1 Seismic (0.2g) 1.5 l.5 to 1

~A. Rapid Drawdown 25 O

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Overbura'en

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EMER6ENCY COOLING _nunn As shownl emma.

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WA TER POND RUSSELLVf LLE NUCLEAR PLANT RUSSELLVILLE, AR KANSAS M 032,0 STABILITY OF EXCAVATED SLOPES 5

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RESULTS OF COA /SOLJOATED DRAINED D/ RECT SHEAR TESTS

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