The drawing is a general drawing for the design of circular pipe culvert in the reconstruction and expansion project of provincial highway, mainly including the general structural drawing of orthogonal single hole circular pipe culvert, oblique circular pipe culvert, structural drawing of splayed portal, structural drawing of circular pipe culvert foundation form in soft foundation section, structural drawing of drop well, structural drawing of side ditch culvert, etc.
Main technical standards:
(1) Design load: highway - Class I;
(2) Environment category of the structure: Class I;
(3) Design safety level: Level III
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Design calculation:
① In this general drawing, the strength and crack width of the section are checked according to the bearing capacity limit state and the normal service limit state.
② Calculation theory: the calculation is based on rigid pipe joint, that is, the deformation of the pipe joint is not considered, and the friction between the soil column at the top of the culvert and the surrounding fill is not considered. The angle distribution method is used for calculation, and the semi infinite elastic body theory is used for calculation.
③ The pipe joint reinforcement is analyzed according to the pure bending section. The two-way reinforcement pipe wall is used to set two layers of reinforcement inside and outside the circle. The pipe joint reinforcement is designed by crack control.
④ The vehicle load is used as a variable action, and the self weight of the fill and pipe body is used as a permanent action for effect combination according to the specification requirements.
⑤ Soil weight: calculated according to soil column weight theory, internal friction angle φ=35 °, soil volume weight: 18KN/m3.
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Construction:
① Pipe joints are divided into standard pipe joints and auxiliary pipe joints for length adjustment. The standard pipe joint is 2m long, and the auxiliary pipe joint is 1m and 0.5m long.
② The water flow condition at the portal is good, and the splayed wall type portal should be used. When the straight portal is used, the conical slope protection should be used to ensure the stability of the end wall and improve the drainage.
③ Pipe joint structure: the gap between pipe joints is filled with asphalt yarn and asphalt oakum soaked in asphalt, and the outer ring is fully coated with two layers of hot asphalt.
④ Foundation structure: C20 concrete foundation is adopted for general soil section, and sand gravel cushion is adopted below; C20 reinforced concrete is used in soft foundation section.
![[Hubei] 19 general drawings for the design of circular pipe culvert project of provincial highway (including splayed wall) - Figure 1](https://fd.co188.com/group1/M03/FE/69/rBBhIF1JLr6AA3R3AAHbQz7BmNM781-1.jpg!610c.jpg "[Hubei] 19 general drawings for the design of circular pipe culvert project of provincial highway (including splayed wall) - Figure 1")
![[Hubei] Standard Drawing for Design of Circular Pipe Culvert Project of Provincial Highway 19 sheets (including splayed wall) - Figure 2](https://fd.co188.com/group1/M03/FE/69/rBBhIF1JLr6AA3R3AAHbQz7BmNM781-2.jpg!610c.jpg "[Hubei] Standard Drawing for Design of Circular Pipe Culvert Project of Provincial Highway 19 sheets (including splayed wall) - Figure 2")
