Page 184 - Water Standards
P. 184
pansion joint should be 1 5-2cm. The quality of pipeline joints and
expansion joints shall meet design requirements and the requirements
in Section 2 7 of this specification, and hermetic sealing shall be en⁃
sured.
4 The section length of a precast reinforced concrete pipe is de⁃
termined according to specific conditions of process, transportation
and installation, and generally should not be longer than 5m. Socket
type pipes shall be selected with priority as the pipe section form. Dur⁃
ing pipe section hoisting, the concrete strength shall meet the design
requirements. When there are no design requirements, it shall not be
lower than 70% of design strength. The position, form and sealing
material of the settlement joints and expansion joints, and the sealing
material of pipe section joints shall all meet the design requirements.
The sealing material shall be firmly bonded, and tightly plugged,
without leakage phenomenon. The allowable deviation for precast pipe
installation shall meet the requirements in Table 3 8 5.
Table 3 8 5 Allowable deviation of precast pipe installation
Unit: mm
Allowable
No. Item
deviation
1 Axis displacement of pipes ±5
2 Internal surface elevation difference between adjacent two pipes 3
3 Width of settlement joint and expansion joint ±5
4 Gap difference in the same connecting joint of a socket pipe ±5
3 8 6 The construction of penstocks made of other materials shall
meet the following requirements:
1 The civil construction of penstocks made of other materials
shall be carried out according to design requirements.
2 According to the material and performance of different pipe⁃
1 7 7