Special curve cast-in-place reinforcement concrete construction plan
The performance pool is one of the most important projects in the entire aquarium project, and also one of the projects with the greatest difficulty in construction. The horizontal projection of the pool is "cashew nut shaped". It is tangent connected by a variety of curves with different curvatures, and the perimeter length of the pool is 180.713m; The whole performance pool is of cast-in-place reinforced concrete structure, with wall thickness of 500mm, bottom plate thickness of 350mm, and the elevation of the upper structure of the bottom plate is -6.5m. The cushion cap and bearing tie beam are below the bottom plate, and the excavated cast-in-place pile is below the cushion cap. The top elevation of the pool wall is+0.5m. The underground workshop surrounding the performance pool is Room 10. The floor of the workshop is at the same elevation as the bottom of the performance pool. The workshop is arranged around the pool. The perimeter of the cast-in-place reinforced concrete outer wall is 216.667m, the wall thickness is 400mm, and the bottom plate is 150mm thick. The lower structure of the bottom plate is the same as that of the performance pool. The top plate is cast-in-place reinforced concrete beam plate, and the upper elevation of the top plate is+0.3m. The exhibition pool and No. 10 working room are each closed concrete walls. The perimeter of No. 10 working room is 216.67m, and the perimeter of the exhibition pool is 180.71m. According to the national specifications, the above length has far exceeded the upper limit of the maximum distance between deformation joints in the specifications. That is to say, from the construction point of view, there is no guarantee that there will be no deformation cracks after one continuous pouring of concrete. In several design disclosures, we have negotiated with the Hong Kong designer on this issue, hoping to explain the design intent and propose technical measures to prevent cracks without deformation joints, The Hong Kong designer only insisted that no joints should be left, no cracks should appear, no leakage, etc. due to the needs of the use function, but did not propose special technical measures to achieve this requirement. When we proposed that we should make post cast strips (deformation joints), the designer insisted on not accepting our suggestions. After formulating this plan, after several discussions with the engineering department of the aquarium (the construction unit) and the technical personnel of the supervision company on this issue, we decided to conduct technical consultation with the Technology Development Company of China Academy of Building Materials Science (hereinafter referred to as the Technology Development Company of the Building Materials Institute), and follow the suggestions of the Technology Development Company of the Building Materials Institute, The concrete of this project shall be shrinkage compensating concrete (that is, UEA-M concrete shrinkage compensating expansion agent shall be added to the concrete), and the technical development company of the Building Materials Institute shall provide technical guidance during the construction process. In terms of construction layout, considering that the performance of No. 10 workshop only needs to meet the requirements of preventing underground water immersion, it is decided to set 4 deformation joints (post cast strip), The construction length of each section shall be controlled within the limited length. For the performance pool, considering the addition of UEA-M, a post cast strip is left in the new version of the structural drawing. Although its length exceeds the specification, no cracks can be found in theoretical calculation. However, due to many reasons for concrete shrinkage and deformation, it is difficult to ensure that no cracks will be found. For this, the consulting unit guarantees that no leakage will occur after technical treatment. The performance pool and No. 10 working room are required to be structurally self waterproof, with concrete strength grade of C35 and impermeability grade of P10. The earthwork and cast-in-place pile construction of the project began in late September 1994. Now the earthwork has been excavated to the design elevation, and the cast-in-place pile construction has been completed.
