摘要
山区公路高填方路基的稳定性受填料强度和水文地质条件的影响。2023年,某高速公路K83+400 m至K83+800 m段出现了严重病害,包括路基沉降、路面开裂、结构破坏、抗滑桩倾斜以及挡土板渗水。现场调研推测病害成因是填料密实度不足和地下水位显著上升所致。通过GNSS技术实时监测病害路段边坡变形,其变化趋势直接反映路基边坡的稳定状态。基于有限元极限分析开展如下数值模拟:利用板单元模拟抗滑桩,并按配筋图计算截面等效强度及刚度参数,被某经典边坡案例验证有效;指定边坡两侧水头高度,计算边坡的稳态渗流场,另外可用水压力恒为0的排水线模拟深层泄水孔;先后考虑抗滑桩加固、地下水渗流以及排水措施的影响,计算典型断面高填方边坡在5种不同工况下的稳定性。对比模拟结果与实际地下水位及滑移面,证实了该高填方路基失稳的致因为地下水渗流,也验证了相关病害处治措施的有效性。研究还发现边坡稳定性安全系数与抗滑桩桩前相对地下水位η呈负相关,当η大于0.4时,安全系数的下降趋势将加剧。研究结果可为山区公路的设计、施工、运营以及应急处理提供参考。
The stability of high-fill embankments on mountain roads is affected by fill strength and hydrogeological conditions.In 2023,an expressway section between K83+400 m and K83+800 m encountered serious problems,such as roadbed settlement,pavement cracking,structural damage,stabilizing pile tilting,and retaining wall seepage.On-site investigations indicated that the presumed causes of the accident were insufficient fill material compaction and a significant increase in groundwater levels.The real-time monitoring of slope deformation in damaged sections using GNSS technology directly reflects the stability of the embankment.Based on finite element limit analysis,the following numerical simulations were conducted:plate elements were used to simulate stabilizing piles,and the equivalent strength and stiffness parameters of the sections were calculated according to the reinforcement diagram,which was validated by a classic slope case;the water head height on both sides of the slope was specified to calculate the steady-state seepage field of the slope,and a drainage line with zero water pressure was used to simulate deep drainage holes;the impacts of stabilizing pile reinforcement,groundwater seepage,and drainage measures were sequentially considered;and the stability of the high-fill slope at a typical section was calculated for five different cases.By comparing the simulation results with the actual groundwater level and slip surface,it was confirmed that groundwater seepage directly led to instability of the high-fill embankment and the effectiveness of the disease treatment measures was verified.Further research revealed that the safety factor for the actual embankment slope was negatively correlated with the relative groundwater level in front of the stabilizing pile.When it exceeded 0.4,the downward trend of the safety factor was aggravated.This study provides an important reference for the design,construction,operation,and emergency management of mountainous highways in China.
作者
杨洲
程晓辉
关文
尹斌
王新泽
YANG Zhou;CHENG Xiao-hui;GUAN Wen;YIN Bin;WANG Xin-ze(School of Civil Engineering,Tsinghua University,Beijing 100084,China;Yunnan Construction and Investment Holding Group,Kunming 650501,Yunnan,China)
出处
《中国公路学报》
北大核心
2025年第5期1-10,共10页
China Journal of Highway and Transport
基金
香丽高速公路特殊结构隧道建造技术风险和优化研究项目(云交科教[2018]36号)。
关键词
路基工程
高填方边坡
有限元极限分析
抗滑桩
地下水渗流
现场监测
subgrade engineering
high fill slope
finite element limit analysis
stabilizing pile
groundwater seepage
on-site monitoring
