發(fā)布時間：2018-01-26 00:30

  本文關鍵詞： 盾構法隧道 縱向應力松弛 松弛機理及效應 現(xiàn)場實測　出處：《巖土工程學報》2017年05期 　論文類型：期刊論文

【摘要】：為研究軟土盾構法隧道的縱向應力松弛特性,對錢江隧道典型斷面的管片體、襯砌環(huán)面的縱向應力松弛特性和環(huán)間縱向連接螺栓軸力的時變特性進行了長達兩年的現(xiàn)場實測。結果表明,軟土盾構法隧道管片體的縱向應力松弛將經歷周期性劇烈波動、動態(tài)穩(wěn)定、逐漸衰減、趨于穩(wěn)定四個階段的演變,其縱向應力平均值由3 MPa逐漸松弛為1.2MPa,在達到穩(wěn)定前至少需要1 a時間;與此同時,襯砌環(huán)縫面上的接觸應力松弛也經歷上述4個階段的演變,其接觸應力平均值由2 MPa逐漸松弛為1 MPa,在達到穩(wěn)定前至少需要18個月;隧道環(huán)間連接螺栓軸力先減小、然后暫時穩(wěn)定、最后增大,且在經歷了2 a的顯著波動后仍未穩(wěn)定表明隧道縱向應力松弛導致接觸狀態(tài)仍處于復雜的演變過程之中,其最終穩(wěn)定需要更長時間。軟土盾構法隧道的縱向應力松弛是襯砌環(huán)間接觸調整、土體 隧道結構接觸調整和螺栓體松弛三大要素的時變性及其共同作用的結果,可導致隧道環(huán)面接縫剛度降低、環(huán)間抗剪承載力下降、環(huán)間接縫的防水密封性能弱化等,應引起工程界重視。
[Abstract]:In order to study the longitudinal stress relaxation characteristics of soft soil shield tunnel, the segment body of typical section of Qianjiang tunnel is studied. The longitudinal stress relaxation characteristics of lining ring surface and the time-varying characteristics of axial force of longitudinal connection bolt between rings have been measured in the field for up to two years. The results show that. The longitudinal stress relaxation of soft soil shield tunnel segment body will undergo periodic violent fluctuation, dynamic stability, gradual attenuation, and tend to the evolution of the four stages of stability. The average longitudinal stress relaxes gradually from 3 MPa to 1.2 MPA, and it takes at least 1 year before reaching stability. At the same time, the contact stress relaxation on the annular surface of the lining also experienced the evolution of the above four stages, and the average contact stress gradually relaxed from 2 MPa to 1 MPa. At least 18 months before stabilization is reached; The axial force of the connecting bolt between the rings of the tunnel first decreases, then stabilizes temporarily, and finally increases. And after two years of remarkable fluctuation, it is still not stable, which indicates that the longitudinal stress relaxation of the tunnel leads to the complex evolution of the contact state. The longitudinal stress relaxation of soft soil shield tunnel is the adjustment of contact between lining rings. The time variation of contact adjustment and bolt relaxation of the tunnel structure and the results of the joint action can result in the decrease of the stiffness of the tunnel ring joint and the decrease of the shear bearing capacity between the rings. The waterproofing sealing performance of ring joint is weakened, which should be paid attention to by engineering circles.
【作者單位】： 同濟大學地下建筑與工程系;同濟大學巖土與地下工程教育部重點實驗室;中鐵第四勘察設計院集團有限公司;
【基金】：國家重點基礎研究發(fā)展計劃(“973”計劃)項目(2015CB057806) 國家自然科學基金項目(51378389) 山東省自然科學基金項目(ZR2016EEQ13,ZR2014EEQ28)
【分類號】：U455.43
【正文快照】： 3.中鐵第四勘察設計院集團有限公司,湖北武漢430063)軟土盾構法隧道在施工過程中受到盾構千斤頂推*通訊作者(E-mail:menyanqing@126.com)力作用向前延伸,使得隧道在全長范圍及相當長時間內存在明顯的縱向預壓應力,這種縱向應力對襯砌環(huán)間滲漏水防治和縱向變形控制等至關重要[1

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