大吨位“二阶段受力混凝土叠合梁法”施工技术

Construction Technology of Large Tonnage Two-Stage Forced Concrete Composite Beam Method

通过对里底电站左岸溢洪道坝顶预制梁施工,探讨“二阶段受力混凝土叠合梁”(预制+现浇)替代大吨位混凝土预制梁设计、施工关键技术、各项指标,解决施工条件有限情况下大吨位混凝土预制梁吊装难题。对于跨越河流、交通干道、桥梁等下部无法布设支撑进行现浇筑,但吊装又受限的大砘位混凝土桥梁采用“二阶段阶受力混凝土叠合梁”是一个较好的选择,技术经济指标较好。

Through the construction of prefabricated beam on dam crest of left bank spillway of Lidi Hydropower Station,this paper discusses the key technologies and indexes of design and construction of two-stage stressed concrete composite beam replacing large-tonnage concrete prefabricated beam.It solves the difficult problem of lifting large-tonnage concrete precast beam under limited construction conditions.It is a better choice to adopt two-stage stress concrete composite beam for cast-in-situ concrete bridge with large inrush where support can not be laid across rivers,trunk roads,bridges and other lower parts but lifting is limited.