摘要
三峡库区某大桥承台采用双壁钢吊箱围堰结构进行施工,由于库区水位差近20m,需对封底混凝土厚度进行设计。根据最高水位抗浮和最低水位抗沉需求,对封底混凝土厚度进行理论计算,最终以最低水位抗沉计算得到的混凝土厚度5.12m作为理论厚度。考虑钢护筒不同位置的影响,采用有限元法将封底混凝土理论厚度修正为5.55m。修正后的封底混凝土较厚,出于经济性考虑,采用设置栓钉连接件的方式将封底混凝土厚度优化为2.65m。结果表明:栓钉连接件抗剪能力满足围堰结构粘结力需求,混凝土结构受力满足抗裂需求,优化设计较好地解决了大水位差下封底混凝土较厚的问题,确保了封底混凝土施工安全,且经济性较好。
The pile cap of a bridge in the Three Gorges Reservoir Region is constructed with the aid of the double-walled steel box cofferdam.Due to that the water-level fluctuates about 20 m in the reservoir region,the thickness of base-sealing concrete in the cofferdam is quite critical.In the theoretical calculation,the buoyancy and sinking resistant requirements of the cofferdam at the highest and lowest water levels were taken into account.As a result,the concrete thickness of5.12 mgained at the lowest water level was determined as the theoretical thickness.Considering the influence of the location of steel casings,the theoretical thickness was modified to be 5.55 m on the base of the calculation result.After optimization,the thickness of the base-sealing concrete was relatively big,which was not an ideal option from the perspective of economy.Then,the thickness was modified to 2.65 mvia the utilization of stud connectors.The results show that the anti-shearing performance of the stud connectors can meet the bonding requirements of the cofferdam,the load bearing capacity of the concrete structure is sufficient for the anti-cracking demand,which is a good solution for treating the base-sealing concrete thickness under large water-level difference.The construction safety of the base-sealing concrete is ensured,and the solution is also superior in term of economy.
作者
王明慧
陈永亮
李开兰
王碧军
张桥
WANG Ming-hui;CHEN Yong-liang;LI Kai-lan;WANG Bi-jun;ZHANG Qiao(Yu-Qian Railway Co.,Ltd.,Chongqing 400014,China;The Fifth Engineering Co.,Ltd.,China Railway 11 Bureau Group Co.,Ltd.,Chongqing 400037,China)
出处
《世界桥梁》
北大核心
2020年第5期6-10,共5页
World Bridges
基金
中国铁路总公司科技研究开发计划项目(K2018G057)
2020年重庆市技术创新与应用发展专项面上项目(cstc2020jscx-msxm0584)。
关键词
桥梁工程
大水位差
钢吊箱围堰
封底混凝土
混凝土厚度
粘结力
栓钉连接件
bridge engineering
large water-level difference
steel box cofferdam
base-sealing concrete
concrete thickness
bond strength
stud connector
