Mo. Code Regs. Ann. tit. 10, § 22-3.020
PURPOSE: The purpose of this rule is to itemize the basic requirements and standards that apply to all permits.
(6) New dams constructed wholly of cohesive materials (such as clays) and having a foundation of cohesive materials or rock, can be expected to withstand significant earthquake shaking if it can be shown that other required design factors of safety for slope stability are met. Therefore, only new dams located in Bollinger, Butler, Cape Girardeau, Dunklin, Mississippi, New Madrid, Pemiscot, Ripley, Scott, Stoddard and Wayne Counties must meet the requirements for slope stability during earthquake loading while dams located in other counties do not unless 10 CSR 22- 3.030(5) applies to them. Bedrock accelerations and earthquake intensities are listed in Table 4. Table 1—Required Design Factors of Safety for Slope Stability Earth and Rock Conventional Dams
Loading Condition End of construction, full reservoir* Steady seepage, full reservoir* Steady seepage, maximum reservoir** Sudden draw down, from full to empty reservoir (if applicable) Earthquake***, steady seepage, full reservoir*
*Full reservoir means water level is at the water storage elevation. **Maximum reservoir means water level is at maximum water level attained during the spillway design flood or at the dam crest elevation, whichever is lower.
***Earthquake loading will vary according to dam location in relation to seismic source zones and downstream environmental zones. (See Table 4).
Table 2—Required Design Factors of Safety Concrete Conventional Dams
Failure Mode Overturning
Sliding
Structural integrity
Earthquake*** any mode
*Full reservoir means water level is at the water storage elevation. **Maximum reservoir means water level is at maximum level attained during the spillway design flood.
***Earthquake loading will vary according to dam location in relation to seismic source zones and downstream environmental zones. (See Table 4).
Table 3—Required Design Factors of Safety for Slope Stability Industrial Water Retention Dams
Loading Condition Starter dam, end of construction, full reservoir* Any other stage of construction, full reservoir*, steady seepage Any other stage of construction, maximum reservoir*, steady seepage Completed dam, full reservoir*, steady seepage Completed dam, maximum reservoir**, steady seepage Earthquake***, steady seepage, full reservoir*
*Full reservoir means water level is at the water storage elevation. **Maximum reservoir means water level is at the maximum level attained during the spillway design flood or at the dam crest elevation, whichever is lower.
***Earthquake loading will vary according to dam location in relation to seismic source zones and downstream environmental zones. (See Table 4).
Factor of Safety 1.5 1.3 1.5 1.3 1.5 1.3 1.0
Factor of Safety 1.4 1.3 1.0 1.5 1.3 1.0 Dam Type Conventional or Industrial
Industrial
ZONE A Dunklin Mississippi New Madrid Pemiscot
* PMA is Probable Maximum Acceleration of bedrock which is determined as a fraction of the acceleration of gravity (g = 32.2 fps2) for the six zones in Missouri (see 10 CSR 22-1.020(41)). ** See 10 CSR 22-2.020(3) for clarification.
*** Modified Mercalli Intensity.
MATT BLUNT Stage of Construction
Completed
Starter dam
dam is completed
Zone
ZONE B Bollinger Butler Cape Girardeau Ripley Scott Stoddard Wayne Table 4—Required Design Acceleration For Earthquake Design
A B C D E F
ZONE C Carter Howell Iron Madison Oregon Perry Reynolds St. Francois Ste. Genevieve Shannon
Special Descriptions New dams less than 50 feet in height New dams greater than 50 feet in height** New dams** After starter dam is finished and before final New dams**
PMA* 0.31 g 0.28 g 0.26 g 0.23 g 0.20 g 0.17 g
ZONE D Crawford Dent Douglas Franklin Jefferson Ozark Phelps Pulaski St. Louis St. Louis City Taney Texas Washington Wright .75PMA*
.75PMA* .5PMA*
.75PMA*
Intensity** IX—X IX VIII—IX VIII VII—VIII VII
ZONE E Audrain Barry Barton Bates Benton Boone Caldwell Callaway Camden Carroll Cass Cedar Chariton Christian Clark Cole Cooper Dade Dallas Gasconade Greene Henry Hickory Howard Jackson Jasper Johnson Knox Laclede Lafayette Lawrence 10 CSR 22-3
Environmental Class
I II
.5PMA*
.5PMA* .2PMA*
.5PMA*
ZONE E (cont.) Lewis Lincoln Linn Livingston McDonald Macon Maries Marion Miller Moniteau Monroe Montgomery Morgan Newton Osage Pettis Pike Polk Ralls Randolph Ray St. Charles St. Clair Saline Scotland Shelby Stone Vernon Warren Webster III
.25PMA*
.4PMA* .1PMA*
.2PMA*
ZONE F Adair Andrew Atchison Buchanan Clay Clinton Davis Dekalb Gentry Grundy Harrison Holt Mercer Nodaway Platte Putnam Schuyler Sullivan Worth Dam Type Conventional or Industrial
Industrial
*PMP is Probable Maximum Precipitation. **Existing dam means a dam which was completed by August 13, 1981 or which was started prior to August 13, 1981 and completed by August 13, 1987.
***See 10 CSR 22-2.020(3) for clarification. ****100 Yr. is the 100 year frequency rainfall event. Table 5—Required Spillway Design Flood Precipitation Values
Stage of Construction Completed
New dam less than 50 feet in height*** New dam greater than 50 feet in height Starter dam After starter dam is finished and before final dam is completed Special Descriptions Any existing dam**
Any
Any Environmental Class I .75PMP*
.75PMP*
.75PMP* .5PMP*
.75PMP* II III .5PMP* 100 Yr.****
.5PMP* 100 Yr.****
.5PMP* 100 Yr.***** .2PMP* .1PMP*
.5PMP* .2PMP* AUTHORITY: sections 236.400, 236.405, 236.415, 236.435, 236.440 and 236.465, RSMo 1986.* Original rule filed April 14, 1981, effective Aug. 13, 1981. Amended: Filed June 14, 1984, effective Jan. 1, 1985. Amended: Filed Aug. 15, 1988, effective Jan. 1, 1989. Amended: Filed May 15, 1990, effective Nov. 30, 1990. *Original authority: 236.400, RSMo 1979; 236.405, RSMo 1979, amended 1993, 1995; 236.415 RSMo 1979, amended 1995; 236.435, RSMo 1979; 236.440, RSMo 1979; and 236.465, RSMo 1979.