盾构掘进地面隆陷及潮汐作用江底盾构隧道性状研究

发布时间：2018-10-05 13:08

【摘要】：目前国内水下盾构隧道建设方兴未艾,其施工环境效应及结构稳定性的研究应运而生。本文研究在杭州水下盾构隧道的建设背景下展开,依托于杭州庆春路过江隧道的工程实践,通过现场试验和理论计算研究了盾构掘进引起的地面隆陷及钱塘江潮汐对隧道结构受力性状的影响,旨在深入认识水下盾构隧道施工环境扰动及其长期结构性状。本文研究内容总体上分为2部分,分别为盾构掘进引起的地面隆陷和钱塘江潮汐作用下盾构隧道的受力性状。 (一)盾构掘进引起的地面隆陷庆春路隧道建设期间,对盾构掘进引起的地面隆陷进行了大量的现场监测,并实时记录了盾构掘进参数。通过实测分析,总结了杭州软土中盾构掘进引起地面竖向位移的特征和规律,并对各传统地面沉降计算理论的适用性进行评析。在实测基础之上,引入土力学和流体力学的若干基本理论计算盾构掘进引起的地面隆陷。主要创新点如下： (1)提出了盾构非水平掘进时的地面隆陷Mindlin解数值积分算法。 (2)在实测基础之上发现横向地面注浆隆起符合高斯分布,与地层损失沉降叠加,提出考虑注浆隆起效应的广义Peck公式。 (3)基于源汇法推导得到在隧道围土不同收敛模式下的地面沉降计算公式,并在实测基础之上进行了经验性改进,提供了一种盾构隧道施工地层损失沉降估算的简单可靠方法。 (4)提出了一种划分地层损失沉降与固结沉降的简单实用方法。 (5)提供了一种盾构施工扰动超孔隙水压力及地面固结沉降的理论计算方法。 (6)提出了一种考虑盾构掘进速度和停机时间的地面沉降计算理论。 (7)探讨了同步注浆的时空效应,提出了考虑注浆效率和注浆分布模式的地面隆陷计算方法。 (8)提出了一种基于切口超挖控制的地面隆陷计算方法。 (二)钱塘江潮汐作用下盾构隧道的受力性状庆春路隧道在建设期间设计实施了结构健康监测系统,监测项目包括隧道位置钱塘江水位、隧道围压、衬砌钢筋应变、衬砌水平直径收敛以及隧道纵向沉降。依托于该健康监测系统的现场实测,主要有以下创新性研究： (1)分析了钱塘江水下盾构隧道围压及钢筋应变与水位的相关性。 (2)针对隧道上覆土层透水性的不同,提出了2种水下盾构隧道衬砌设计模型,并以现场实测验证了其中之一的合理性。 (3)采用惯用计算法计算水位波动引起的衬砌钢筋应变变化,并根据现场实测数据对计算弯矩进行了经验性修正,使其计算内力可用于衬砌结构应力应变分析。 (4)基于上述两种水下盾构隧道衬砌设计模型,出于隧道结构安全的考量,对钱塘江极限容许水位进行了预测。
[Abstract]:At present, the construction of underwater shield tunnel is in the ascendant, and the study of its environmental effect and structural stability arises at the historic moment. In this paper, under the background of the construction of the underwater shield tunnel in Hangzhou, it is based on the engineering practice of crossing the river tunnel of Qingchun Road in Hangzhou. Based on field test and theoretical calculation, the influence of ground subsidence caused by shield tunneling and Qiantang River tide on the mechanical behavior of tunnel structure is studied in order to deeply understand the disturbance of underwater shield tunnel construction environment and its long-term structural characteristics. The research contents of this paper are divided into two parts, which are the mechanical behavior of shield tunnel caused by shield tunneling and tidal action of Qiantang River. (1) during the construction of Qingchun Road Tunnel caused by shield tunneling, a lot of on-site monitoring was carried out on the ground uplift caused by shield tunneling, and the parameters of shield tunneling were recorded in real time. The characteristics and laws of vertical ground displacement caused by shield tunneling in soft soil in Hangzhou are summarized through the actual measurement and analysis, and the applicability of the traditional land subsidence calculation theory is evaluated. Based on the measured results, some basic theories of soil mechanics and fluid mechanics are introduced to calculate the ground subsidence caused by shield tunneling. The main innovations are as follows: (1) the numerical integration algorithm for Mindlin solution of ground subsidence in shield tunneling is proposed. (2) based on the measured results, it is found that the transverse surface grouting uplift accords with Gao Si distribution and superimposes with formation loss and settlement. A generalized Peck formula considering grouting uplift effect is proposed. (3) based on the method of source and sink, the calculation formula of ground subsidence under different convergent modes of surrounding soil is derived, and the empirical improvement is made on the basis of actual measurement, which provides a simple and reliable method for estimating the ground loss settlement in shield tunnel construction. (4) A simple and practical method for distinguishing ground loss settlement from consolidation settlement is proposed. (5) A theoretical calculation method of disturbance excess pore water pressure and ground consolidation settlement in shield construction is provided. (6) A theory of land subsidence calculation considering shield tunneling speed and stopping time is proposed. (7) the space-time effect of synchronous grouting is discussed, and the calculation method of surface subsidence considering grouting efficiency and grouting distribution mode is proposed. (8) A calculation method of ground subsidence based on notch overdigging control is proposed. (2) the mechanical characteristics of shield tunnel under the action of Qiantang River Tide during the construction period of Qingchun Road Tunnel, a structural health monitoring system was designed and implemented. The monitoring items include the water level of Qiantang River, the tunnel confining pressure, and the strain of lining reinforcement. The horizontal diameter convergence of the lining and the longitudinal settlement of the tunnel. Based on the field measurements of the health monitoring system, the following innovative studies are carried out: (1) the correlation between the confining pressure and the reinforcement strain and the water level of the underwater shield tunnel in Qiantang River is analyzed. (2) two kinds of underwater shield tunnel lining design models are put forward in view of the different permeability of the overlying soil layer, and the rationality of one of them is verified by field measurement. (3) the strain change of lining steel bar caused by water level fluctuation is calculated by using the customary calculation method, and the calculated moment is modified empirically according to the measured data in the field, so that the calculated internal force can be used to analyze the stress and strain of lining structure. (4) based on the above two kinds of underwater shield tunnel lining design models and considering the tunnel structure safety, the limit allowable water level of Qiantang River is predicted.
【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】：U455.43

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