【摘要】：鑒于既有力學模型在分析三維隧道施工力學問題時存在精度不高、計算資源要求高和計算時效不能滿足工程要求等諸多困難,將隧道圍巖視為半無限大或無限大彈性體,以作用于洞壁和掌子面處的等效作用力模擬隧道開挖效應,建立了一種深埋圓形隧道的三維分析模型.基于Mindlin解和Kelvin解分別推導了掌子面在洞口附近和掌子面遠離洞口兩種工況下圍巖位移的積分計算公式,并編制了相應的計算程序,然后將待開挖介質(zhì)視為"支護體",通過剛度分析將支護反力引入力學模型,推導了圍巖變形的求解方程,可以快速計算隧道圍巖變形場和圍巖對支護結(jié)構剛度需求的量化值.研究結(jié)果表明:兩種工況下圍巖位移的分布規(guī)律基本一致,掌子面距離洞口較近時,隧道縱剖面圍巖軸向位移最大值的解析和數(shù)值結(jié)果分別為6.1 mm和5.5 mm,隧道橫截面掌子面處徑向位移最大值分別為2.4 mm和2.6 mm,誤差分別為9.8%和8.3%;在掌子面距離洞口較遠的工況下,隧道縱剖面圍巖軸向位移最大值分別為6.0 mm和5.7 mm,誤差為5.0%;對于任選的一組隧道圍巖和支護結(jié)構參數(shù),考慮支護反力后計算得到的圍巖縱向變形與數(shù)值分析結(jié)果吻合較好,超前位移分別為3.6 mm和3.0 mm,最終位移分別為9.1 mm和8.5 mm,誤差分別為16.7%和6.6%;大崗山隧道2#壓力管道的超期變形的計算結(jié)果和監(jiān)測結(jié)果分別為0.4 mm和0.4 mm,最終變形分別為1.0 mm和1.1 mm,誤差分別為0和10%.基于變形控制標準和新建力學模型可對圍巖的剛度需求進行量化計算并指導支護結(jié)構設計參數(shù)的確定.
[Abstract]:In view of the difficulties of the existing mechanical model in analyzing the mechanical problems of 3D tunnel construction, such as low precision, high computational resource requirements, and the calculation time can not meet the engineering requirements, the surrounding rock of the tunnel is regarded as a semi-infinite or infinite elastic body. Based on the equivalent force acting on the wall and face of the tunnel to simulate the tunnel excavation effect, a three-dimensional analysis model of the deep buried circular tunnel is established. Based on the Mindlin solution and the Kelvin solution, the integral calculation formulas of surrounding rock displacement of the face near the hole and the face far away from the hole are derived, and the corresponding calculation program is worked out, and then the medium to be excavated is regarded as a "supporting body". Through stiffness analysis, the supporting reaction force is introduced into the mechanical model, and the solving equation of surrounding rock deformation is deduced, which can quickly calculate the quantitative value of tunnel surrounding rock deformation field and the requirement of surrounding rock to the stiffness of supporting structure. The results show that the distribution of displacement of surrounding rock is basically the same under two working conditions. When the face is close to the hole, the analytical and numerical results of the maximum axial displacement of surrounding rock in longitudinal section of tunnel are 6.1 mm and 5.5 mm, respectively. The maximum radial displacement at the face of cross section is 2.4 mm and 2.6 mm, respectively, and the error is 9.8% and 8.3% respectively. The maximum axial displacement of surrounding rock in longitudinal section of tunnel is 6.0 mm and 5.7 mm, respectively under the condition that the face of the tunnel is far away from the opening of the tunnel. For the selected parameters of surrounding rock and supporting structure of tunnel, the longitudinal deformation of surrounding rock calculated after considering the support reaction is in good agreement with the numerical analysis results, and the advance displacement is 3.6 mm and 3.0 mm, respectively. The final displacement is 9.1 mm and 8.5 mm, error is 16.7% and 6.6%, respectively. The calculated results and monitoring results of the pressure pipeline in Dagangshan Tunnel are 0.4 mm and 0.4 mm, respectively. The final deformation is 1.0 mm and 1.1 mm, respectively. The error is 0 and 10, respectively. Based on the deformation control standard and the new mechanical model, the stiffness requirement of surrounding rock can be calculated quantitatively and the design parameters of supporting structure can be determined.
【作者單位】： 北京交通大學城市地下工程教育部重點實驗室;北京市安全生產(chǎn)科學技術研究院;北京京投城市管廊有限責任公司;北京市市政工程研究院;
【基金】：國家自然科學基金重點項目(U1234210,51134001)
【分類號】：U451.2
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本文編號：2342238