Page 23 - Analysis and Design of Energy Geostructures

xxiv List of symbols

Roman symbols
Symbol Variable name Unit measure
Characteristic resisting load N
R c;k
Characteristic shaft load N
R s;k
Characteristic base load N
R b;k
Measured resistance load N
R c;m
Excess radius m
R exc
Settlement ratio
R s
R 1 First characteristic distance in Mindlin’s solution m
R 2 Second characteristic distance in Mindlin’s solution m
Material or product characteristic resistance Variable
R k
Reynolds number
Re; Re x
Critical Reynolds number
Re c
Effective radius of the heat exchanger m
R eff
Time-independent thermal resistance C/W
R ghe
Maximum vertical distance between the highest and lowest peaks of a m
R max
structure asperities
Normalised roughness
R n
0 Thermal resistance of the grouting material m C/W

R
c
0 Thermal resistance of the pipe m C/W

R
p

0 Time-independent thermal resistance of geothermal heat exchanger per m C/W
R
ghe
unit length
Time-independent thermal resistance of geothermal heat exchanger per m 2 C/W
Rv ghe
unit surface

0 Convection time-independent thermal resistance per unit length m C/W
R
conv

0 Convection time-independent thermal resistance of pipe per unit length m C/W
R
conv;p
Convection time-independent thermal resistance per unit surface m 2 C/W
Rv conv
0 Conduction time-independent thermal resistance of pipe per unit length m C/W

R
cond;p

0 Conduction time-independent thermal resistance of concrete per unit m C/W
R
cond;c
length
Conduction time-independent thermal resistance of geothermal heat m 2 C/W
Rv cond
exchanger per unit surface
0 Radiation time-independent thermal resistance per unit length m C/W

R
rad
Radiation time-independent thermal resistance per unit surface m 2 C/W
Rv rad
0 i-th thermal resistance of the circuit per unit length m C/W

R
i
i-th thermal resistance of the circuit per unit surface m 2 C/W
Rv i

0 Thermal resistance of the soil per unit length m C/W
R
soil
Total thermal resistance C/W
R T
0 Total thermal resistance per unit of length m C/W

R
T
Contact resistance m 2 C/W
Rv C
Total thermal resistance per unit of surface m 2 C/W
Rv T
3
Body force in r direction N/m
R

Dimensionless distance
~ R

Dimensionless distance
~ ~ R
Recompression ratio
RR
Spacing m
s
Pipe absolute surface roughness m
s R
Maximum crack spacing m
s r;max
s q ; s c ; s γ Shape factor
Distance from the tunnel intrados m
s i