地铁下穿高速公路大型桩基托换技术

Large pile foundation underpinning technology for metro under-passing highway

深圳地铁8号线一期梧桐山站—沙头角站区间线路在下穿罗沙高架桥左线时,罗沙高架桥Z11号及Z12号桥台处需要进行桩基托换处理。托换施工须在不影响上部交通正常通行的情况下进行,采用主动托换法进行托换,设计顶升荷载约1 500 t,施工上部结构竖向位移控制在1 mm以内。顶升施工采用PLC同步顶升控制系统,并采用电子位移计、计算机应变仪、倾斜仪等进行施工监测,确保了施工安全。

When the section line of Shenzhen metro line 8 Phase I Wutongshan station-Sha Tau Kok station was under-passing the left track of the Luosha viaduct,the pile foundation replacement treatment was needed at Z11 and Z12 abutments of Luosha viaduct.The underpinning construction must be carried out without affecting the normal upper traffi c.Using the active replacement method to carry out the underpinning,the designed lifting load is about 1500 t,while the vertical displacement of the construction superstructure is controlled within 1 mm.PLC synchronous lifting control system is used for the jacking construction.Electronic displacement meter,computer strain gauge and inclinometer are adopted for construction monitoring to ensure construction safety.