海底沉管隧道管段沉降与应变研究

发布时间：2018-05-12 14:43

本文选题：沉管隧道 + 不均匀沉降　；参考：《浙江大学》2015年硕士论文

【摘要】：随着沉管隧道技术的日益成熟,更多的跨河(海)工程选择沉管法来施工。然而作为一种特殊水下隧道,管段的不均匀沉降及变形将导致管段开裂、渗漏等严重问题,直接影响到隧道的寿命和安全。本文主要通过理论推导及有限元模拟对沉管隧道管段沉降进行深入分析,通过实测对沉管隧道管段变形进行研究。本文主要创新点和结论如下： (1)在修正的弹性地基梁法基础上,对K的取值方法和接头约束方式进行了改进,使之更符合实际工程,提出了新的计算沉管隧道纵向不均匀沉降的方法。并以舟山沈家门港海底沉管隧道为例,进行了详细的算例分析。 (2)把沉管隧道基础层和地基土层整体定义为复合地基,用弹簧代表基础层,Kelvin模型代表地基土,提出采用三参数模型来模拟复合地基。在弹性地基梁解的基础上,根据对应性原理和三参数模型本构关系,利用拉普拉斯变换推导出沉管隧道三参数模型的沉降解析解。 (3)假定软土地区海底沉管隧道地基土为Kelvin模型,车辆荷载是随时间变化的波动荷载形式,引入粘弹性地基梁模型,利用模态叠加法进而给出了三种情况下沉管隧道的竖向位移、弯矩和地基反力的解答。结合天津海河沉管隧道工程实例,分析了车辆速度、地基土模量对沉管隧道竖向位移及弯矩的影响。发现车速对管段振动的频率产生影响,且车速越快,振动越剧烈,但对振幅没有影响；地基模量对管段振动的振幅影响很大,且地基模量越小,振幅越大,但对振动周期没有影响。 (4)采用光纤光栅传感器对舟山沈家门港海底沉管隧道的管节应变进行监测,并对实测数据进行分析,研究了各截面测点实测应变值随时间的变化规律以及潮汐荷载对管段应变的影响。(5)利用MIDAS GTS软件对舟山沈家门港海底沉管隧道进行了三维模拟,得到了各管段的不均匀沉降,及管段应力变形的结果,并且与第二章理论计算隧道纵向不均匀沉降值及实测值进行比对分析。
[Abstract]:With the development of sinking tunnel technology, more and more cross-river (sea) projects are constructed by pipe sinking method. However, as a special kind of underwater tunnel, the uneven settlement and deformation of the pipe section will lead to serious problems such as cracking and leakage of the pipe section, which will directly affect the life and safety of the tunnel. In this paper, the settlement of pipe section of immersed tube tunnel is deeply analyzed by theoretical derivation and finite element simulation, and the deformation of pipe section of immersed tunnel is studied by actual measurement. The main innovations and conclusions of this paper are as follows: 1) on the basis of the modified beam method of elastic foundation, the method of calculating the value of K and the constraint mode of joint are improved to make it more suitable for practical engineering. A new method for calculating the longitudinal uneven settlement of immersed tunnel is put forward. A detailed numerical example is given for the submarine tunnel of Shenmen Port in Zhoushan. 2) the submersible tunnel foundation layer and the foundation soil layer are defined as composite foundation, and the Kelvin model of foundation layer is used to represent the foundation soil. A three-parameter model is proposed to simulate the composite foundation. On the basis of the beam solution of elastic foundation, according to the correspondence principle and the constitutive relation of the three-parameter model, the settlement analytical solution of the three-parameter model of the immersed tube tunnel is derived by Laplace transformation. (3) assuming that the submersible tunnel foundation soil in soft soil area is Kelvin model, the vehicle load is a fluctuating form with time variation, the viscoelastic foundation beam model is introduced, and the vertical displacement of three cases of sinking tube tunnel is given by using the modal superposition method. Solutions to bending moment and foundation reaction. In this paper, the influence of vehicle speed and soil modulus on vertical displacement and bending moment of submerged pipe tunnel is analyzed with the example of Tianjin Haihe immersed tunnel. It is found that the velocity has an effect on the vibration frequency of the pipe segment, and the faster the speed, the more intense the vibration, but not the amplitude, and the greater the amplitude of the foundation modulus, the greater the vibration amplitude of the pipe segment, and the smaller the foundation modulus is, the greater the vibration amplitude is. But it has no effect on the vibration cycle. FBG sensor is used to monitor the strain of pipe joint in the tunnel of Shenmen Harbor, Zhoushan, and the measured data are analyzed. The variation law of measured strain value with time and the influence of tidal load on the strain of pipe section are studied. The 3-D simulation of the tunnel in Shenjiaogang, Zhoushan, is carried out by using MIDAS GTS software, and the uneven settlement of each section is obtained. And the results of stress and deformation of the pipe segment are compared with the theoretical calculation of longitudinal uneven settlement of tunnel and the measured value in chapter 2.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U459.5;U455.46

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