An analytical solution for
the transient temperature field of hydraulic tunnel lining structures in high
ground temperature environments is presented using the Laplace transform. The
temperature stress characteristics of the lining are examined, and the elastic
resistance method is applied to derive the elastic temperature stress
components. Using data from the Bulunkou hydropower station in Xinjiang, the
transient temperature and stress fields of the lining structure are computed.
The analysis incorporates the tensile strength criterion and the intensity
factor at the crack tip to evaluate structural damage. The authors propose
effective temperature control measures based on the following findings: (1)
During early age, the temperature within the lining temperature field surges,
peaking on approximately the 7th day with inner and outer wall temperatures
reaching 37 ℃ and 56 ℃, respectively. (2) The circumferential stress on the outer wall
achieves 2.2 MPa, indicating a tensile stress state, whereas the radial stress
reaches 2.7 MPa, reflective of a compressive state. (3) The structural
integrity of the lining is predominantly influenced by temperature and its
stability. Enhancements in stability are achievable using lowheat cement, precise control of concrete′s
molding temperature, and rigorous construction monitoring. A reduction of the
final concrete hydration heat by 50 kJ/kg can decrease the temperature
differential between the lining′s inner and outer walls
by approximately 1.85 ℃. Moreover, increasing the
molding temperature can expedite the hydration heat release period, thus
reducing the temperature variance across the lining.
LI Feifei
,
JIANG Haibo
,
XIANG Pengfei
,
WEI Gang
. Temperature Control and
Crack Prevention in High Ground Temperature Hydraulic
Tunnel Linings: Insights From Hydration Heat Effect of Concrete[J]. Tunnel Construction, 2024
, 44(6)
: 1262
-1273
.
DOI: 10.3973/j.issn.2096-4498.2024.06.013