摘要
为了解隧道下穿富水强风化砂岩地层施工对既有铁路的影响,依托某电缆隧道下穿广深铁路工程,通过理论分析、数值模拟与现场监测开展了相关研究,并分析了具体施工措施对隧道及地表变形控制的影响。结果表明:当不考虑地表列车荷载和地层富水时,开挖及顶进力为地表沉降、隧道变形的主要影响因素;当单独考虑列车荷载或地层富水弱化作用时,列车荷载会使得下穿段地表沉降和隧道拱顶沉降增大,而地层富水弱化对隧道进出口段沉降及下穿段底部隆起影响较大;当同时考虑列车荷载和地层富水时,隧道拱顶沉降及下穿段路基沉降均会大幅增加。对比分析现场监测、Peck公式预测和数值模拟计算结果,可知数值模拟结果与不考虑地层富水弱化时的Peck公式预测结果十分吻合,但由于其未考虑加固止水措施,地表沉降大于现场监测结果。电缆隧道下穿广深铁路现场施工严格执行现场监测和变形控制措施,将地表沉降值和隧道拱顶沉降值分别控制在6 mm和10 mm之内,隧道底部隆起控制在5 mm以下,可以保障项目的顺利实施与列车的运行安全,并为同类型工程提供一定的经验参考。
To study the influence of the water-rich intensely weathered sandstone formation tunnel underpass construction on the exisiting railway,relying on a cable tunnel crossing underneath the Guangzhou-Shenzhen railway project,the related research was conducted through theoretical estimation,numerical simulation and on-site monitoring,and the influence of the specific construction measures on the tunnel deformation control was analyzed.The results show that excavation and jacking force is the main factor affecting the surface subsidence and tunnel deformation without taking the train load and the water-rich rock formation into consideration.When the train load or the water-rich weakening effect of formation are considered alone,the train load causes the increase of surface subsidence and tunnel vault subsidence of underpass section,while the deteroration of the water-rich rock formation has a greater influence on the settlement of tunnel entrance and exit the tunnel upheaval of underpass section.Taking both the train load and the water-rich rock formation into account,tunnel vault subsidence and surface subsidence of underpass section will grow greatly.Comparing the results of on-site monitoring,Peck formula and numerical simulation,it can be seen that the numerical simulation results are consistent with the Peck formula prediction results without considering the water-rich rock formation,while it is larger than on-site monitoring results without considering the reinforcement water-stop measures.The on-site monitoring and deformation control measures are strictly realized in the construction of the cable tunnel crossing underneath the Guangzhou-Shenzhen Railway,and the settlement values of ground surface and the tunnel vault are controlled below 6 mm and 10 mm respectively,and the upheaval of the tunnel bottom is controlled below 5 mm,ensuring the smooth implementation of the project and the safe operation of the train,which provides a certain reference for similar projects.
作者
潘鹏旭
陈伟
郑京承
PAN Peng-xu;CHEN Wei;ZHENG Jing-cheng(Changsha Railway Survey and Design Co.,Ltd.,Changsha 410000,China;School of Civil Engineering,Central South University,Changsha 410075,China)
出处
《科学技术与工程》
北大核心
2023年第29期12714-12720,共7页
Science Technology and Engineering
基金
国家自然科学基金(51608537)
湖南省自然科学基金(2022JJ30715)。
关键词
富水强风化砂层
顶管隧道
PECK公式
下穿铁路
列车荷载
water-rich intensely weathered sandstone formation
pipe jacking tunnel
Peck formula
underneath railway
train load
