地铁荷载作用下饱和土体衬砌隧道与轨道系统的动力响应

发布时间：2018-06-03 09:54

本文选题：饱和土 + 地铁　；参考：《浙江大学》2014年博士论文

【摘要】：我国城市轨道交通的建设规模迅速扩大,所引起的环境振动问题也日益突出。利用已有基础理论成果,揭示地铁列车荷载作用下轨道、衬砌和周围饱和土体的振动机理,准确预测地铁运行引起周边环境振动,具有非常重要的现实意义,相关的研究成果可以为线路设计、轨道设计、隔振减振设计等提供依据和标准。在我国沿海地区,大量地铁建在饱和软土地基中,采用饱和介质理论模拟地铁周围土体比较接近实际情况。本文基于Biot饱和多孔介质理论,以地铁荷载、轨道系统、衬砌隧道以及周围饱和土体为研究对象,首次用解析方法较为系统地研究了地铁列车作用下轨道-衬砌-饱和土体耦合振动的动力特性。开展了如下研究： 1.采用Biot饱和多孔介质模型来模拟土体,以解析方法研究了饱和土体全空间中无衬砌圆形隧洞在移动点荷载作用下的三维动力响应。引入两类势函数来表示土骨架的位移和孔隙水压力,使用Fourier变换方法,在不同环向模态下利用修正Bessel方程来求解各势函数,结合边界条件,得到频率-波数域内位移及孔隙水压力的解答,最后进行双重Fourier逆变换得到时间-空间域内的响应解。计算了饱和土体位移响应随速度变化的曲线及空间分布等,并根据算例结果分析了荷载速度、土体渗透性等对土体位移响应的影响。 2.采用无限长圆柱壳来模拟衬砌,采用Biot饱和多孔介质模型来模拟土体,以解析方法研究了全空间饱和土中圆形衬砌隧道在简谐点荷载作用下的三维动力响应。根据外荷载特征,直接将外荷载和位移展开成波传播形式,对饱和土体采用与之前类似的处理方式,结合边界条件,求得了位移及孔隙水压力的解答。计算了隧道周围土体中一点、隧道仰拱及其下方土体的动力响应,并根据计算结果分析了荷载振动频率和土体渗透性对土体和衬砌位移响应及土体孔压的影响。 3.以解析方法研究了饱和土体全空间中圆形衬砌隧道在移动简谐点荷载作用下的三维动力响应。结合之前两部分的工作,使用Fourier变换方法,求得了位移及孔隙水压力的解答。计算了隧道衬砌及周围土体响应的空间分布及频谱曲线等,并根据算例结果分析了荷载速度、荷载振动频率、土体渗透性、模量等对位移及孔压的影响。 4.在之前工作的基础上,首次以解析方法建立了“轨道结构-衬砌-饱和土体全空间”耦合的三维动力响应模型。将荷载模拟成单个移动简谐点荷载和一系列符合列车空间尺寸的移动荷载。在频率-波数域内,联立轨道结构动力方程和仰拱处的位移频率响应函数,获得钢轨、轨道板、隧道仰拱处的位移以及轨道板与衬砌之间的作用力。再利用所求位置的频率响应函数和轨道板与衬砌之间的作用力,获得变换域中隧道结构和土体的位移、孔压。最终通过双重Fourier逆变换,可得到钢轨、轨道板、隧道结构、饱和土体的时域响应。研究了荷载移动速度、荷载振动频率、土体渗透性等对轨道、衬砌及饱和土体响应的影响。
[Abstract]:The construction scale of urban rail transit in China is expanding rapidly, and the environmental vibration problems are becoming more and more prominent. Using the existing basic theoretical results to reveal the vibration mechanism of the track, lining and surrounding saturated soil under the subway train load, and accurately predict the vibration of the surrounding environment caused by the subway operation, which is of great practical significance. The research results can provide basis and standard for line design, track design, vibration isolation and vibration reduction design.
In the coastal areas of China, a large number of subways are built in the saturated soft soil foundation, and the saturated medium theory is used to simulate the soil around the subway. Based on the theory of Biot saturated porous media, this paper studies the subway load, track system, lining tunnel and surrounding saturated soil as the research object. The analysis method is more systematic for the first time. The dynamic characteristics of coupling vibration between track and lining and saturated soil under the action of metro train are studied.
1. using the Biot saturated porous medium model to simulate the soil, the three-dimensional dynamic response of the circular tunnel without lining in the full space of the saturated soil under the moving point load is analyzed by the analytical method. Two kinds of potential functions are introduced to represent the displacement of the soil skeleton and the pore water pressure. The Fourier transformation method is used to make use of the correction under different circumferential modes. The Bessel equation is used to solve every potential function, and the solution of the displacement and pore water pressure in the frequency wave number domain is obtained by combining the boundary conditions. Finally, the response solution in the time space domain is obtained by the double Fourier inversion. The curves of the displacement response of the saturated soil with the velocity variation and the space distribution are calculated, and the load speed is analyzed according to the results of the calculation. The influence of permeability and soil permeability on soil displacement response is also discussed.
2. an infinite cylindrical shell is used to simulate the lining and the Biot saturated porous medium model is used to simulate the soil. The three-dimensional dynamic response of the circular lining tunnel under the simple harmonic load is analyzed by the analytical method. The external load and displacement are directly spread into the wave propagation form according to the characteristics of the external load, and the saturated soil is used. The solution of the displacement and pore water pressure is solved with the boundary condition, and the response of a point in the soil around the tunnel, the dynamic response of the tunnel inverted arch and the soil below is calculated, and the effect of the vibration frequency of the load and the permeability of the soil on the displacement response of the soil and lining and the pore pressure of the soil is analyzed.
3. the three-dimensional dynamic response of the circular lining tunnel under the moving simple point load is studied by the analytical method. With the work of the previous two parts, the solution of the displacement and pore water pressure is solved by using the Fourier transformation method. The spatial distribution and spectrum curve of the response of tunnel lining and circumference of surrounding soil are calculated. The effects of load speed, load vibration frequency, permeability and modulus of soil on displacement and pore pressure are analyzed based on the results of calculation.
4. on the basis of previous work, a three-dimensional dynamic response model of "track structure lining saturated soil whole space" was established for the first time. The load was simulated as a single moving simple point load and a series of moving loads in line with the space size of the train. In the frequency wave number domain, the dynamic equations and the pitching of the simultaneous orbital structure were raised. With the displacement frequency response function of the arch, the displacement of the rail, the track plate, the tunnel arch and the force between the track plate and the lining are obtained. The displacement of the tunnel structure and the soil mass and the pore pressure in the transform domain are obtained by using the frequency response function of the position and the force between the track plate and the lining. The response of the rail, track plate, tunnel structure and saturated soil in time domain can be obtained. The effects of load moving velocity, load vibration frequency, soil permeability and so on on the response of track, lining and saturated soil are studied.
【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：U211.3;U452.28

【参考文献】