Construction method for mid-span closure section of prestressed concrete continuous beam bridge and continuous rigid framework

Abstract

The invention discloses a construction method for the mid-span closure section of a prestressed concrete continuous beam bridge and a continuous rigid framework. The construction method includes the steps that when closing the mid-span closure section, hanging baskets are not removed first, but the hanging baskets on both sides of the closure section are moved in the direction away from the mid-span closure section first, then lifting frames and stiff skeletons of the closure section are installed, then rebars are bound and concrete of the closure section is poured, and finally, the lifting frames and the hanging brackets are removed. According to the core of the method, when pouring the concrete of the closure section, the hanging baskets are used as counterweights without any additionalfacility, only through adjustment of the key process of construction, the construction temporary load of the hanging baskets on a main beam is converted into the favorable prestress, the phenomena ofmid-span down-warping and even cracking can be effectively improved, and the safety of the bridge structure operation period is improved.

Description

technical field [0001] The invention belongs to the technical field of bridge construction and relates to a construction method for a mid-span closing section of a prestressed concrete continuous girder bridge and a continuous rigid frame. Background technique [0002] Prestressed concrete continuous girders and continuous rigid structures are widely used bridge types in my country because of their simple shape, convenient construction, and large spanning capacity; this type of bridge is generally constructed by the hanging basket suspension method. During the construction process, the mid-span is closed The length between sections is generally 2m, the length of the sections is small, and the construction space of the hanging basket is not enough, so it is not suitable to use the hanging basket for construction. After the construction of the section is completed, the steel tendons are stretched to complete the closing of the whole bridge; during the construction of the closing...

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Problems solved by technology

[0002] Prestressed concrete continuous beams and continuous rigid structures are widely used bridge types in my country because of their simple shape, convenient construction, and large spanning capacity; this type of bridge is generally constructed by the hanging basket suspension method. During the construction process, the mid-span is closed The length between the sections is generally 2m, the length of the sections is small, and the construction space of the hanging basket is not enough, so it is not suitable to use the hanging basket for construction. After the construction of the section is completed, the steel tendons are stretched to complete the closing of the whole bridge; during the construction of the closing section, the hanging basket is dismantled in advance, resulting in insufficient compressive stress reserve at the lower edge of the main girder after closing. With the increase of time, due to the loss of prestressed part, shrinkage and creep of concrete and other factors, the main beam will be deflected or even cracked at the mid-span;

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