Open caisson in the municipal engineering construction occasionally met, but seemingly small quantities, but Zimu different, one not careful may have missed. Due to the front of a period of time, the second branch pipe jacking project more, so the settlement of open caisson have a little experience, to share with you now.
1, open caisson in before excavation usually edge at the foot of a sand cushion, thickness generated by the scheme and field actual measurement, the sand cushion sometimes and concrete cushion, so when excavating the earthwork excavation top elevation on the calculation to the sand cushion, cushion concrete by the demolition of Tong Zimu calculation.
2, caisson dig to design elevation, at the bottom of the ultra excavation by bill of quantities is not measured, but bottom sealing concrete if not in the project stated does not measure the over excavation, according to actual amount, square sign after measurement.
3, open caisson bottom plate and tank wall connection part in the design will be indicated by bar or the connector, but list tend to the omission, after the declaration of the supplement the subheading. The bar, in addition to the production and installation of steel bar can calculate engineering quantity of steel.
4, the caisson reserved hole brick masonry block, sinking in place after the demolition, corresponding measure.
5, as well as caisson work, pipe jacking holes in the reinforcement item sometimes missed.
6, a steel ladder spacing is 36cm, because it can be well calculated for each division, a.
So, please provide more valuable opinions.
(Zhou Yong)