浅埋超大直径双圆顶管侧穿高压铁塔桩基预加固方案  

Study on Pre-reinforcement Scheme of Pile Foundation of Shallow-buried Super-large Double Circular Pipe Jacking Side-crossing High-voltage Tower

作　　者：康兰方 苗冰阳 马海军 梁斌[2] 张波 KANG Lanfang;MIAO Bingyang;MA Haijun;LIANG Bin;ZHANG Bo(The Forth Engineering Co.,Ltd.of CCCC Second Highway Engineering Bureau Co.,Ltd.,Luoyang Henan 471013,China;School of Civil Engineering,Henan University of Science and Technology,Luoyang Henan 471000,China)

机构地区：[1]中交二公局第四工程有限公司,河南洛阳471013 [2]河南科技大学土木建筑学院,河南洛阳471000

出　　处：《兰州工业学院学报》2024年第3期30-36,共7页Journal of Lanzhou Institute of Technology

基　　金：国家自然科学基金(U1604135);中交二公局第四工程有限公司重点科技研发项目(2023-04-10);河南科技产学研合作项目(2015HNCXY011)。

摘　　要：以深圳市铁岗-石岩水库水质保障工程2#顶管侧穿王洋Ⅰ线N14高压铁塔为背景,对浅埋超大直径双圆顶管侧穿高压铁塔桩基预加固方案进行系统研究。提出管幕支护、“管幕支护+钻孔灌注咬合桩+旋喷桩”、“管幕支护+微型桩+旋喷桩”3种预加固方案,通过MIDAS/GTS建立数值模型,分析3种方案加固效果。结果表明:方案一加固效果不理想;方案二加固效果明显提升,对桩基沉降最为显著,较方案一降低53%;采用方案三,塔基整体沉降、水平、纵向位移及相邻桩基沉降差较方案二分别减少42%、20%、16%及19%,更能有效控制桩基稳定;加固后,塔基最大沉降为5.49 mm,最大水平位移为3.99 mm,最大纵向位移为2.28 mm,相邻塔基最大差异沉降为0.95 mm,基础最大局部倾斜为0.03%,均满足施工控制标准。方案三加固技术能较好地控制铁塔桩基沉降,保证高压铁塔的安全和正常使用,可为类似工程提供借鉴。In this paper,based on the N14 high voltage tower of the 2#pipe jacking side crossing WangyangⅠline of Shenzhen Tiegang-Shiyan reservoir water quality assurance project,the pre-reinforcement scheme of pile foundation of shallow-buried super-large double circular pipe side crossing high voltage tower is systematically studied.Three reinforcement schemes,“pipe curtain support”,“pipe curtain support+borehole perfusion occlusal pile+rotary jet pile”and“pipe curtain support+micro pile+rotary jet pile”,are proposed.Numerical models are established by MIDAS/GTS to analyze the reinforcement effects of the three schemes.The results show that the reinforcement effect of the scheme 1 is not ideal,while the reinforcement effect of the scheme 2 is significantly improved,and the settlement of pile foundation is most significant,which is 53%lower than that of scheme 1.However,compared with the scheme 2,the overall settlement,horizontal displacement,longitudinal displacement and settlement difference of adjacent pile foundation in the scheme 3 are reduced by 42%,20%,16%and 19%,respectively,which can effectively control the stability of pile foundation.After reinforcement,the maximum settlement of the tower is 5.49mm,the maximum horizontal displacement is 3.99mm,the maximum longitudinal displacement is 2.28mm,the maximum differential settlement of adjacent towers is 0.95mm,and the maximum local tilt of the foundation is 0.03%,which meets the construction control standards.The reinforcement technology of“tube curtain support+micro pile+rotary jet pile”can better control the settlement of pile foundation of the tower,ensure the safety and normal use of the high pressure tower,and provide reference for similar projects.

关 键 词：超大直径双圆顶管 高压铁塔 预加固方案 管幕支护 隔离桩 现场监测 

分 类 号：U455[建筑科学—桥梁与隧道工程]