17
Temporary Support
Rock Reinforcement
Modelling details of the reinforcement units (notably the typeof
bonding and allowable axial strain) are significant.
Typically Safety Factors of 1.5 against tensile failure of bar
for temporary units and 2.0 for permanent units are usually
considered.
Interaction Diagram
for Reinforced Concrete DesignAccording to BS 8110, Part 1:1997
& Part 3:1985
Input Data: TABLE BAL - Concept I - 20m - K=0.7
SHOTCRETE 350mm - PILLAR (30mm Relaxation)
h = 350 mm Intrados: cover 50 mmb = 1000 mm diameter 10 mm
fcu = 25 N/mm2
spacing 150 mm
fy = 460 N/mm2
As1 = 524 524 mm2
Es = 210000 kN/mm2
Extrados: cover 20 mmdiameter 10 mm
Partial material factors: spacing 150 mmmc = 1,5 concrete As2 =
524 524 mm
2
ms = 1,05 reinforcement
M N d1 = 55 mm169,770 2279 0,260 0,055 d2 = 25 mm144,520 2212
0,253 0,047 d = 295 mm119,290 2205 0,252 0,03975,000 2150 0,246
0,02440,420 2101 0,240 0,01314,390 2086 0,238 0,0050,310 2075 0,237
0,000
18,520 2056 0,235 0,0062,940 2039 0,233 0,0017,690 2002 0,229
0,003
47,280 2008 0,230 0,01560,000 1989 0,227 0,020
0,000 0,0000,000 0,0000,000 0,0000,000 0,0000,000 0,0000,000
0,0000,000 0,0000,000 0,0000,000 0,0000,000 0,0000,000 0,0000,000
0,0000,000 0,0000,000 0,0000,000 0,0000,000 0,0000,000 0,0000,000
0,0000,000 0,0000,000 0,0000,000 0,0000,000 0,0000,000 0,0000,000
0,0000,000 0,0000,000 0,0000,000 0,0000,000 0,0000,000 0,0000,000
0,0000,000 0,0000,000 0,0000,000 0,0000,000 0,0000,000 0,0000,000
0,0000,000 0,000
Interactive Diagram
-0,1
0
0,1
0,2
0,3
0,4
0,5
0,6
-0,02 -0,01 0,00 0,01 0,02 0,03 0,04 0,05 0,06 0,07 0,08
0,09
= [M/fcu.b.h2]
=
[N
/fcu.b
.h]
Concrete Capacity
Including tension reinforcement
Capacity: tension +compression reinforcementSection Forces
Interaction Diagram
for Reinforced Concrete DesignAccording to BS 8110, Part 1:1997
& Part 3:1985
Input Data: TABLE BAL - DESIGN MODEL 20m - K=0.7
SHOTCRETE 350mm + LAG D2 (Ixx=773,45cm4, H=160mm, 2No32mm +
1No25mm) @ 1000mm
HALF TOP HEADING (at Relaxation 30mm)
h = 350 mm Intrados: cover 95 95 mmb = 1000 mm diameter 25 0
mm
fcu = 25 N/mm2
spacing 500 100 mm
fy = 460 N/mm2
As1 = 982 0 982 mm2
Es = 210000 kN/mm2
Extrados: cover 95 95 mmdiameter 32 0 mm
Partial material factors: spacing 1000 100 mmmc = 1,5 concrete
As2 = 1608 0 1608 mm
2
ms = 1,05 reinforcement
M N d1 = 95 mm0,000 0,000 d2 = 95 mm0,000 0,000 d = 255 mm0,000
0,0000,000 0,000
66,000 2554 0,292 0,02271,810 2667 0,305 0,02353,880 2343 0,268
0,01830,400 2128 0,243 0,01013,040 2173 0,248 0,00413,530 2088
0,239 0,0045,670 1925 0,220 0,002
12,230 1818 0,208 0,00425,970 1680 0,192 0,0085,680 1588 0,181
0,002
20,300 1507 0,172 0,00746,740 1426 0,163 0,01575,650 1364 0,156
0,02596,970 1233 0,141 0,032
116,630 1176 0,134 0,038136,700 1126 0,129 0,045136,010 952
0,109 0,04498,860 1132 0,129 0,03299,340 1085 0,124 0,032
0,000 0,0000,000 0,0000,000 0,0000,000 0,0000,000 0,0000,000
0,0000,000 0,0000,000 0,0000,000 0,0000,000 0,0000,000 0,0000,000
0,0000,000 0,0000,000 0,0000,000 0,0000,000 0,0000,000 0,0000,000
0,0000,000 0,0000,000 0,0000,000 0,0000,000 0,0000,000 0,0000,000
0,0000,000 0,0000,000 0,000
Interactive Diagram
-0,2
-0,1
0
0,1
0,2
0,3
0,4
0,5
0,6
-0,02 -0,01 0,00 0,01 0,02 0,03 0,04 0,05 0,06 0,07 0,08
0,09
= [M/fcu.b.h2]
=
[N
/fcu.b
.h]
Concrete Capacity
Including tension reinforcement
Capacity: tension +compression reinforcementSection Forces
N-M interaction diagrams for shotcrete line based on UDEC
derived data
Temporary Support
Shotcrete Capacity