黄土盾构下穿不同地下非连续管线的模型试验OA北大核心CSTPCD
Model Tests on Underpassing of Different Underground Discontinuous Pipelines by a Shield in Loess
针对城市盾构隧道施工下穿既有输气管线引起管线沉降与受力问题,以河南省某在建高速公路为工程背景,进行室内模型试验和有限元数值模拟.考虑不同非连续管线接头间距、接头刚度和管隧间距的影响,探讨管隧正交工况下,隧道开挖对非连续管线沉降、弯矩及管土接触应力的影响.研究结果表明:黄土盾构正交下穿管线存在沉降集中区,在该区范围内,管线接头与管段相对刚度比的大小对管线平均沉降增长速率影响较大,相对刚度比由1.30减小至0.21,非连续管线平均沉降增长速率增大1.5倍;相对刚度比相对大小对非连续管线沉降和弯矩起到决定性作用;通过定义非连续管线综合刚度比,揭示不同综合刚度比下非连续管线最大沉降变化规律和管线最大正负弯矩相对变化规律,其中综合刚度比与管线最大沉降服从3次多项式拟合函数,管线的最大正弯矩值随着最大负弯矩值的改变服从4次多项式拟合函数;管线的管土接触应力变化均呈现"双峰型"变化,管土接触峰值应力随着接头间距的增大而增大;数值模拟表明,管线最大沉降随着管隧间距增大而呈现折线型减小,该转折点出现在管隧间距与隧道开挖直径比为1处.
Aiming at the problem of pipeline settlement and stress caused by urban shield tunnel construction underneath an existing gas pipeline,indoor model tests and finite element numerical simulations are carried out with an under-construction highway in Henan Province as the engineering background.Considering the effects of different discontinuous pipe joint spacing,joint stiffness and pipe-tunnel spacing,the effects of tunnel excavation on settlement,bending moment and pipe-soil contact stresses of discontinuous pipes under pipe-tunnel orthogonal conditions are investigated.The research results show that:a settlement concentration zone exists in loess shield orthogonal down through the pipeline,and in the range of the zone,the size of the pipeline joints and pipe section relative stiffness ratio of the pipeline average settlement growth rate has a greater impact on the pipeline average settlement growth rate,where the relative stiffness ratio is decreased from 1.30 to 0.21,and the average settlement growth rate of the discontinuous pipeline is increased by 1.5 times;relative stiffness ratio of the relative size of the discontinuous pipeline settlement and the bending moment played a decisive role;by defining the integrated stiffness ratio of the discontinuous pipeline,it reveals the maximum settlement change rule of the discontinuous pipeline and the relative change rule of the maximum positive and negative bending moments of the pipeline under different integrated stiffness ratios,in which the integrated stiffness ratio and the maximum settlement of the pipeline obey the 3rd polynomial fitting function,and the maximum positive bending moment of the pipeline obeys the 4th polynomial fitting function along with the change in the maximum negative bending moment value;the changes in the pipe-soil contact stresses of the pipeline are presented with a"bimodal type".Numerical simulation shows that the maximum settlement of the pipeline decreases with the increase of the spacing between the tubes and tunnels,the turning point occurs at the ratio of the spacing between the tubes and tunnels and at the diameter of the tunnel excavation of one.
苏永华;李明
湖南大学 土木工程学院,湖南 长沙 410082
交通运输
地下工程盾构管隧正交沉降模型试验
underground engineeringshieldtube-tunnel orthotropysettlementmodelling tests
《湖南大学学报（自然科学版）》 2024 (003)
59-68 / 10
国家自然科学基金资助项目(52178330),National Natural Science Foundation of China(52178330);河南省交通科技项目(2021J7),Henan Province Traffic Science and Technology Project(2021J7)
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