Conditions of the combined static work of a precast concrete-encased steel conduit and pile grillage

Conclusions

• 1. The original calculation scheme in which the entire static load from the conduit is transmitted to the capping beams does not take into account practically the combined work of the entire structure of the conduit. To provide the combined work of the conduit and capping beams it is necessary to limit the initial opening of the joints due to shrinkage and temperature variations to 0.4–0.5 mm. As the calculations show, this is feasible even at the maximum possible rate of the works.

• 2. The rigidity of the interacting structure of a large-diameter conduit and pile grillage is considerably higher than the rigidity of capping beams, which leads to a decrease of forces in the capping beams and increases the bearing capacity and reliability of the conduit. Consideration of the combined work of the conduit and pile grillage makes it possible to reduce the consumption of reinforcement in the capping beams and to equalize the deformations of the foundation within the section.

• 3. The combined work of precast elements of a concrete-encased steel conduit of a pumped-storage station and pile grillage is provided by welding the embedded parts of the precast elements and capping beams, and also by high-quality sealing of the joints between elements. The static work of the precast structure in this case becomes close to the work of a monolithic structure.