泜河渡槽支撑系统预压施工技术研究

大型渡槽槽身挠度控制要求较严格，要求对其施工支撑系统进行预压，测出排架、地基沉降变形，为支撑系统施工设置预拱值提供依据。因渡槽自身荷载较大，而支撑系统预压最大加载是按其自身荷载的1,2倍考虑，故采用半跨预压方案。首先计算出半跨槽身整体荷载，然后将其分解到主、次梁和板上，根据分布荷载，采用等效预压方式对吨袋进行整体布置，并对地基、支架、垫层进行强度验算，验证整个支撑系统的安全性、可靠性。在地基和模板上布置若干个观测点，通过三级预压方式，测得相关沉降数据。采用二次抛物线函数对数据进行模拟．可以计算出支撑系统各个部位的预拱值，为支撑系统施工提供依据。

Study of the Construction Technology of Pre-compaction on Aqueduct Supporting System

Abstract： The large aqueduct requires the high deflection of design. And the supporting system should be pre- compressed. The deformation of subsidence of shelving and foundation should be measured. These are basis for the set of pre-arch value of the supporting system. With large load of the aqueduct, the maximum load of the supporting system is 1.2 times as much as itself. Thus the half-span pre-compaction scheme is adopted. First, the half-span load is calculated. Then the load is assigned to primary-secondary beam and plate. On the basis of distributed load the ton bags are set by the way of equivalent pre-compaction and the cushions, stands, and foundations are checked. And then the security and reliability of the whole supporting system is checked. By means of three-level pre-compaction, several observation points are arranged on the template and foundation. The concerning subsidence data are obtained. By modeling the data with parabolic function, the pre-arch values of every part of the supporting system are obtained as the basis of support system construction.