【作者】 杨杰；

【导师】 张耀庭；

【作者基本信息】 华中科技大学 ， 防灾减灾工程及防护工程， 2022， 硕士

【摘要】 钢筋桁架混凝土叠合楼板是目前我国工程中最常用的装配式楼板。在我国部分省市已开始推广使用50mm厚的预制底板,并将其应用到密拼式钢筋桁架混凝土叠合板中。相较于工程中常用的底板厚度为60mm的后浇带式钢筋桁架混凝土叠合板,50mm厚的预制底板在施工短暂设计状况下更容易出现裂缝,且密拼式叠合板由于板内密拼拼缝及钢筋桁架的存在,导致其长、短向刚度产生变化,学术界对其能否按整浇板计算双向跨中弯矩的问题上尚存在争议。为此,本文重点针对底板厚50mm的密拼式钢筋桁架混凝土叠合板在设计及施工中存在一些关键技术问题开展研究,主要内容如下:(1)对2块钢筋桁架混凝土预制底板进行了吊装及静力加载试验,结果表明板厚对桁架预制底板刚度及开裂荷载的影响较大。对8块钢筋桁架混凝土叠合板与1块普通混凝土预制实心板进行了静载试验,结果表明:密拼式钢筋桁架混凝土叠合板后浇层厚度与预制层厚度的比值不宜小于1.3,且钢筋桁架应平行于拼缝布置。(2)基于预制底板的吊装及静载试验,结合理论分析与ABAQUS数值模拟,探讨了采用板带法计算预制底板截面应力的合理性,并对常见尺寸的50mm厚的桁架预制底板的吊点、临时支撑布置进行了研究。(3)基于叠合板的静载试验,结合理论分析与ABAQUS数值模拟,对密拼式钢筋桁架混凝土叠合板能否按整浇板计算其双向跨中弯矩进行了探讨。结果表明:对于四边简支的密拼式钢筋桁架混凝土叠合板,根据长跨比对其短跨弯矩进行适当调整,长跨弯矩建议不作调整。(4)依据工程实例,对采用钢筋桁架叠合板的结构进行了经济性及抗震性能的初步分析。结果表明:密拼式叠合板相较于后浇带式叠合板,单方工程造价有所减少;叠合板的厚度一般较现浇板大,致使结构自振周期及抗侧移刚度有所提高。更多还原

【Abstract】 Composite slab with steel-bar truss is the most widely used fabricated slab in engineering at present.In some provinces and cities in China,50 mm thick precast slab has been popularized and applied to composite slab connection without gap.Compared with60 mm thick precast slab commonly used in current projects,the 50 mm thick precast slab is more prone to cracks under short construction and design conditions.In addition,the long and short stiffness of composite slab connection without gap changes due to the connection in the slab and lattice girder,there is still controversy in the academic circles on whether it can calculate the two-way mid span bending moment according to the whole cast-in-place slab.Therefore,this paper focuses on some key technical problems in the design and construction of the composite slab connection without gap that the thickness of precast slab is 50 mm.The details are as follows:(1)The hoisting and static loading tests of two precast slabs were carried out.The results show that the slab thickness has a great influence on the stiffness and cracking load of the precast slab.The static load tests of 8 composite slabs and 1 ordinary concrete precast slab show that the ratio of the thickness of the post cast layer to the thickness of the precast layer of the composite slab connection without gap shall not be less than 1.3,and the lattice girder shall be arranged parallel to the joint.(2)Based on the hoisting and static load test of the precast slabs,combined with theoretical analysis and ABAQUS numerical simulation,the rationality of calculating the sectional stress of the precast slab by the strip method was discussed,and the layout of hoisting point and temporary supports of 50 mm thick precast slabs with common size were studied.(3)Based on the static load test of composite slab,combined with theoretical analysis and ABAQUS numerical simulation,this paper discussed whether the two-way mid span bending moment of the composite slab connection without gap can be calculated according to the whole cast-in-place slab.The results show that the short span bending moment should be adjusted according to the ratio of length to span,and the long span bending moment should not be adjusted.(4)Based on the engineering example,the economy and seismic performance of the structure with composite slabs were preliminarily analyzed.The analysis show that when the structure adopts composite slab connection without gap,compared with the composite slab connection with post pouring stuip,the cost of single square project is reduced;The thickness of composite slab is generally larger than that of cast-in-place slab,resulting in the improvement of the natural vibration period and lateral displacement stiffness of the structure.更多还原