PRHTAs Standard Drawings_Revised GABI Drawings_GABI 9-10.pdf

B (Base)

SEE SPECIAL NOTE 3

CASE 1. STEP-FRONT GABION WITH LIVE SURCHARGE AND 2:1 SLOPE

GABI 09

APRIL-28-2021

GABIONS STEP-FRONT

GRAVITY WALL

STANDARD DRAWING APPROVAL

RECOMMENDED BY: DATE: APPROVED BY:

INTERIM STANDARD DRAWING

3'-0"(OFFSET)

0.2M (8 IN) UNDERDRAIN PIPE

(SEE GENERAL NOTE 5)

T

BACKFILL OR EMBANKMENT

(SEE GENERAL NOTE 3)

SURCHARGE 260 PSF

GEOTEXTILE (SEE GENERAL NOTE 4)

EXISITNG SLOPE

2:1 MAX. SLOPE OR FLATTER

2:1 MAX. SLOPE

OR FLATTER

CENTER LINE OF ROAD

1.52M MIN. FOR STEP-FRONT WALL

IN SITE WHERE LEAN CONCRETE BASE ARE

DIFICULT OR NOT RECOMMENDED BY THE

ENGINEER (SEE GENERAL NOTE 7)

1.

4M

M

IN

WALL ANGLE= 6 DEGREES

EXCAVATION (SEE GENERAL NOTE 8)

LEAN CONCRETE (SEE GENERAL NOTE 6)

H (C

O U

R

SE

S)

*SPECIAL NOTES:

*1. THE DESIGN IS BASED ON THE DESIGN ASSUMPTIONS FOR MATERIAL

PROPERTIES, LOADING CONDITIONS, AND GEOMETRY. DIFFERENCES TO THESE

SHOULD BE EVALUATED TO THE IMPACT TO THE DESIGN.

*2. NOTE THAT THERE IS A DIFFERENT COHESION REQUIREMENT FOR THE

FOUNDATION SOILS FOR TALLER STRUCTURES. SEE: “GABION STANDARD

DRAWING WAS DEVELOPED UNDER THE FOLLOWING CONDITIONS OR

ASSUMPTIONS” NOTES 7C AND 7D

3. ROW LIMITS DEPENDS ON ROW PLANS, SLOPE CONDITIONS AND AS

INSTRUCTED BY THE ENGINEER.

B(BASE)

DESIGN REFERENCES

1. AASHTO LRFD 9th Ed. 2020– BRIDGE DESIGN SPECIFICATIONS

2. PUERTO RICO BUILDING CODE AS AMMENDEND 2018

3. INTERNATIONAL BUILDING CODE (IBC 2018) AND ASCE-7 16

GABION STANDARD DRAWING WAS DEVELOPED UNDER THE FOLLOWING CONDITIONS OR ASSUMPTIONS:

1. EARTHQUAKE – GENERAL MAX EXPECTED ROCK ACCELERATION BASED ON ASCE-7 16 FOR PUERTO RICO (OBTAIN USING ATC

HAZARDS BY LOCATION)

a. ASSUMED SITE LOCATION: PUERTO RICO, RISK CATEGORY II, SITE CLASS “D”

b. PGA= 0.501g (MCEG PEAK GROUND ACCELERATION)

c. FPGA = 1.2 (SITE AMPLIFICATION FACTOR)

d. AS PER AASHTO LRFD 3.10.4 AS = FPGA X PGA =1.2 x 0.501= 0.601g > 0.4g (SEISMIC ANALYSIS IS MANDATORY).

e. FOR MODULAR GRAVITY WALLS (GABION WALL) CAPABLE TO DEFORM, SHALL BE AS AASHTO LRFD C11.6.5.2.2, USE KH = 0.5KH0= 0.3g

2. VERIFY AT STRENGTH LIMIT STATES (FOR OVERALL STABILITY, BEARING, SLIDING ECCENTRICITY AND STRUCTURAL FAILURE)

3. VERIFY AT EXTREME EVENT LIMIT STATE (OVERALL STABILITY FAILURE, BEARING, SLIDING ECCENTRICITY AND STRUCTURAL

FAILURE)

4. FOR LIVE SURCHARGE A MINIMUM OF 260 PSF WAS USED FOR STRENGTH LIMIT STATES (IN CASES WHERE LIVE SURCHARGE IS EXPECTED. WHEN USED IN EXTREME EVENT LIMIT STATE COMBINATION AASHTO LRFD 3.4.1 ALLOWS A REDUCTION IN LIVE LOAD

OR 50% (�EQ = 0.5).

5. ASSUMED UNIT WEIGHT OF GABIONS = 110 PCF

6. �Qi > �Rn IN POUNDS PER SQUARE FEET (PSF) AS PER TABLE

7. ASUMED SOIL PROPERTIES AT WALL BASE, BACKFILL OR SUSTAIN SOIL

a. ASSUMED WEIGHT OF SOIL = 120 PCF

b. ANGLE OF INTERNAL FRICTION (�) = 280

c. COHESION, C= 150 PSF (FOR 1 TO 4 COURSES)

d. COHESION, C=600 PSF (FOR 5 TO 7 COURSES ONLY)

GENERAL NOTES:

1. GABIONS SHALL FOLLOW STANDARD SPECIFICATION 614- GABIONS

2. EMBANKMENT MATERIAL SHALL FOLLOW STANDARD SPECIFICATION 203 – EXCAVATION AND EMBANKMENT.

3. BACKFILL MATERIAL AS PER STANDARD SPECIFICATION 206

4. GEOTEXTILE SHALL FOLLOW STANDARD SPECIFICATION 712- MISCELLANEOUS MATERIALS

5. UNDERDRAIN PIPE SHALL FOLLOW STANDARD SPECIFICATION 605 – UNDERDRAINS

6. CONCRETE FOR WALL BASE (LEAN CONCRETE) SHALL FOLLOW STANDARD SPECIFICATION 305 – LEAN CONCRETE BASE

a. THE LEAN CONCRETE BASE NEED TO BE "ROUGH OR COARSE" TO IMPROVE FRICTION BETWEEN GABION WALL AND

CONCRETE

b. THICKNESS CONCRETE WALL BASE=0.15M, LENGTH=WALL LENGTH, WIDTH=WALL BASE (B FROM TABLE) +0.2M

7. IN SITE LOCATIONS WHERE LEAN CONCRETE BASE ARE DIFFICULT OR NOT RECOMMENDED BY THE ENGINEER AN ALTERNATIVE TO THE LEAN CONCRETE BASE SHALL BE USE T=0.3M OF "1 INCH CRUSH STONE", BUT SHALL BE A SUBSIDIARY OBLIGATION UNDER

STANDARD SPECIFICATION - 614 GABIONS

8. EXCAVATION SHALL FOLLOW STANDARD SPECIFICATION 206 – EXCAVATION FOR STRUCTURES

B (BASE)

1'-6" (OFFSET)

SEE SPECIAL NOTE 3

T

2:1 OR FLATTER

EXISITNG SLOPE

CASE 2. STEP-BACK GABION WITH LIVE SURCHARGE AND 2:1 SLOPE

BACKFILL OR EMBANKMENT

(SEE GENERAL NOTE 3)

(WHEN FAILURE IS AT ROAD EDGE)

EMBANKMENT MATERIAL (SEE GENERAL NOTE 2)

SURCHARGE 260 PSF

GEOTEXTILE (SEE GENERAL NOTE 4)

EXCAVATION (SEE GENERAL NOTE 8)

WALL ANGLE =6 DEGREES

GABI 10

APRIL-28-2021

GABIONS STEP-BACK

GRAVITY WALL

STANDARD DRAWING APPROVAL

RECOMMENDED BY: DATE: APPROVED BY:

INTERIM STANDARD DRAWING

CENTER LINE OF ROAD

IN SITE LOCATIONS WHERE LEAN CONCRETE BASE

ARE DIFFICULT OR NOT RECOMMENDED BY

THE ENGINEER (SEE GENERAL NOTE 7)

0.2M (8 IN) UNDERDRAIN PIPE (SEE GENERAL NOTE 5)

LEAN CONCRETE (SEE GENERAL NOTE 6)

H (C

O U

R S

ES

2:1 FLATTER

OR EXISTING CONDITION

1.

4M

M

IN

1.4M MIN.

*SPECIAL NOTES:

*1. THE DESIGN IS BASED ON THE DESIGN ASSUMPTIONS FOR MATERIAL

PROPERTIES, LOADING CONDITIONS, AND GEOMETRY. DIFFERENCES TO THESE

SHOULD BE EVALUATED TO THE IMPACT TO THE DESIGN.

*2. NOTE THAT THERE IS A DIFFERENT COHESION REQUIREMENT FOR THE

FOUNDATION SOILS FOR TALLER STRUCTURES. SEE: “GABION STANDARD

DRAWING WAS DEVELOPED UNDER THE FOLLOWING CONDITIONS OR

ASSUMPTIONS” NOTES 7C AND 7D

3. ROW LIMITS DEPENDS ON ROW PLANS, SLOPE CONDITIONS AND AS

INSTRUCTED BY THE ENGINEER.

DESIGN REFERENCES

1. AASHTO LRFD 9th Ed. 2020– BRIDGE DESIGN SPECIFICATIONS

2. PUERTO RICO BUILDING CODE AS AMMENDEND 2018

3. INTERNATIONAL BUILDING CODE (IBC 2018) AND ASCE-7 16

GABION STANDARD DRAWING WAS DEVELOPED UNDER THE FOLLOWING CONDITIONS OR ASSUMPTIONS:

1. EARTHQUAKE – GENERAL MAX EXPECTED ROCK ACCELERATION BASED ON ASCE-7 16 FOR PUERTO RICO (OBTAIN USING ATC

HAZARDS BY LOCATION)

a. ASSUMED SITE LOCATION: PUERTO RICO, RISK CATEGORY II, SITE CLASS “D”

b. PGA= 0.501g (MCEG PEAK GROUND ACCELERATION)

c. FPGA = 1.2 (SITE AMPLIFICATION FACTOR)

d. AS PER AASHTO LRFD 3.10.4 AS = FPGA X PGA =1.2 x 0.501= 0.601g > 0.4g (SEISMIC ANALYSIS IS MANDATORY).

e. FOR MODULAR GRAVITY WALLS (GABION WALL) CAPABLE TO DEFORM, SHALL BE AS AASHTO LRFD C11.6.5.2.2, USE KH = 0.5KH0= 0.3g

2. VERIFY AT STRENGTH LIMIT STATES (FOR OVERALL STABILITY, BEARING, SLIDING ECCENTRICITY AND STRUCTURAL FAILURE)

3. VERIFY AT EXTREME EVENT LIMIT STATE (OVERALL STABILITY FAILURE, BEARING, SLIDING ECCENTRICITY AND STRUCTURAL FAILURE)

4. FOR LIVE SURCHARGE A MINIMUM OF 260 PSF WAS USED FOR STRENGTH LIMIT STATES (IN CASES WHERE LIVE SURCHARGE IS EXPECTED. WHEN USED IN EXTREME EVENT LIMIT STATE COMBINATION AASHTO LRFD 3.4.1 ALLOWS A REDUCTION IN LIVE LOAD OR

50% (�EQ = 0.5).

5. ASSUMED UNIT WEIGHT OF GABIONS = 110 PCF

6. �Qi > �Rn IN POUNDS PER SQUARE FEET (PSF) AS PER TABLE

7. ASUMED SOIL PROPERTIES AT WALL BASE, BACKFILL OR SUSTAIN SOIL

a. ASSUMED WEIGHT OF SOIL = 120 PCF

b. ANGLE OF INTERNAL FRICTION (�) = 280

c. COHESION, C= 150 PSF (FOR 1 TO 4 COURSES)

d. COHESION, C=600 PSF (FOR 5 TO 7 COURSES ONLY)

GENERAL NOTES:

1. GABIONS SHALL FOLLOW STANDARD SPECIFICATION 614- GABIONS

2. EMBANKMENT MATERIAL SHALL FOLLOW STANDARD SPECIFICATION 203 – EXCAVATION AND EMBANKMENT.

3. BACKFILL MATERIAL AS PER STANDARD SPECIFICATION 206

4. GEOTEXTILE SHALL FOLLOW STANDARD SPECIFICATION 712- MISCELLANEOUS MATERIALS

5. UNDERDRAIN PIPE SHALL FOLLOW STANDARD SPECIFICATION 605 – UNDERDRAINS

6. CONCRETE FOR WALL BASE (LEAN CONCRETE) SHALL FOLLOW STANDARD SPECIFICATION 305 – LEAN CONCRETE BASE

a. THE LEAN CONCRETE BASE NEED TO BE "ROUGH OR COARSE" TO IMPROVE FRICTION BETWEEN GABION WALL AND

CONCRETE

b. THICKNESS CONCRETE WALL BASE=0.15M, LENGTH=WALL LENGTH, WIDTH=WALL BASE (B FROM TABLE) +0.2M

7. IN SITE LOCATIONS WHERE LEAN CONCRETE BASE ARE DIFFICULT OR NOT RECOMMENDED BY THE ENGINEER AN ALTERNATIVE TO THE LEAN CONCRETE BASE SHALL BE USE T=0.3M OF "1 INCH CRUSH STONE", BUT SHALL BE A SUBSIDIARY OBLIGATION UNDER STANDARD

SPECIFICATION - 614 GABIONS

8. EXCAVATION SHALL FOLLOW STANDARD SPECIFICATION 206 – EXCAVATION FOR STRUCTURES