岩溶地区旋挖钻孔钢套筒设计与施工技术研究

Research on Design and Construction Technology of Rotary Drilling Steel Sleeve in Karst Area

广清高速公路改扩建工程新华高架桥地处岩溶发育地区,紧靠旧桥和周边建筑物之间。在岩溶地区邻近建筑物的嵌岩溶洞桩基施工,传统的冲击钻成孔不能很好地满足施工需要和确保施工安全,该工程采用了可循环使用的长钢套筒旋挖钻施工,从经济性和安全性角度出发,通过对钢套筒的节长、壁厚、接头形式等结构进行设计和对钢套筒的下沉、连接和上拔等施工工艺进行研究,利用旋转静压沉管和液压拔管机拔管等成套技术,快速、安全、无振动施工,有效地减少了施工振动和地面塌陷,确保了周边环境的安全和施工质量,具有良好的社会效益和经济效益。

Xinhua Viaduct of Guangqing highway reconstruction and extension project is located in karst development area,closing to the old bridge and surrounding buildings.In karst area,when constructing the pile foundation of rock socketed karst cave of nearby buildings,the traditional percussion drilling can not meet the construction needs well and ensure the construction safety,thus the long steel sleeve rotary drilling rig is used for the construction of this project.From the perspective of economy and safety,it redesigns the section length,wall thickness and joint form of the steel sleeve and studies the construction technology such as sinking,connection and up-pulling of the steel sleeve.Basing on the unitization technology of the rotary static pressure pipe sinking and hydraulic pipe machine drawing,the new technology can fast and safely construct with no vibration and effectively reduce the construction vibration and ground collapse,ensuring the construction quality and safety of surrounding environment,while achieving good social and economic benefits at last.