摘要
常泰长江大桥主桥为双层钢桁梁斜拉桥。5号墩采用圆端形截面台阶型沉井,沉井下沉过程中需穿越粉质黏土与粉砂互层。沉井着床前,对河床进行预开挖,去除表层硬塑粉质黏土,随后采用台阶渐进式工艺取土下沉:首先在内圈井孔取土,消除十字节点及内隔墙支撑,再进行外圈取土,进一步削弱沉井端部支撑,内外圈交替取土形成台阶型泥面,保持沉井下沉姿态稳定。研发智能化气举取土设备,基于智能辅助决策算法,施工指令智能化下发,取土设备自动化运行,实现井孔范围高效取土;辅以高压旋喷、气水复合射流等破土手段,主动消除特殊地层下隔墙、井壁等盲区支撑;通过下沉反演分析,推算下沉系数与下沉速率关系,控制沉井平稳下沉至设计标高。
The main bridge of Changtai Yangtze River Bridge is a double-deck steel truss girder cablestayed bridge.The No.5 pier adopts a step-shaped open caisson with a round-ended section,during the sinking process of the caisson,it needs to cross the silty clay and silt interbedded layer.Before the open caisson is implanted,the riverbed is pre-excavated to remove the surface hard plastic silty clay,and then the stepped process is used to take the soil and sink.Firstly,the soil is taken from the inner ring well hole to eliminate the cross joint and the inner partition wall support,and then the outer ring soil is taken to further weaken the open caisson end support,and the soil of the inner and outer rings are alternately taken to form a stepped mud surface to keep the open caisson sinking posture stable.The intelligent gas lift soil taking equipment is developed,based on the intelligent auxiliary decision-making algorithm,the construction instructions are issued intelligently,and the soil taking equipment is operated automatically to realize the efficient soil taking in the borehole range.With the help of high-pressure jet grouting,airwater composite jet and other soil breaking methods,the blind area support such as partition wall and shaft wall under special strata is actively eliminated.Through the sinking inversion analysis,the relationship between the sinking coefficient and the sinking rate is calculated,and the open caisson is controlled to sink steadily to the design elevation.
作者
管政霖
郭万中
刘修成
GUAN Zhenglin;GUO Wanzhong;LIU Xiucheng(CCCC Second Harbor Engineering Co.,Ltd.,Wuhan,Hubei430040,China;Key Laboratory of Large-span Bridge Construction Technology,Wuhan,Hubei430040,China;Research and Development Center of Transport Industry of Intelligent Manufacturing Technologies of Transport Infrastructure,Wuhan,Hubei430040,China;China Communications 2nd Navigational Bureau 2nd Engineering Co.,Ltd.,Chongqing401121,China)
出处
《施工技术（中英文）》
CAS
2024年第8期66-71,80,共7页
Construction Technology
基金
2019年度交通运输行业重点科技项目(2019-MS1-011)。
关键词
桥梁工程
沉井
智能化
取土
支撑
反演
下沉
bridges
open caisson
intelligent
soil taking
supports
inversion
sinking
作者简介
管政霖,工程师,E-mail:624384374@qq.com。
