现代隧道技术
現代隧道技術
현대수도기술
MODERN TUNNELLING TECHNOLOGY
2014年
6期
35-40
,共6页
申林方%王志良%魏纲%伍曾
申林方%王誌良%魏綱%伍曾
신림방%왕지량%위강%오증
盾构隧道%被动极限支护压力%开挖面稳定性
盾構隧道%被動極限支護壓力%開挖麵穩定性
순구수도%피동겁한지호압력%개알면은정성
Shield tunnel%Passive limit support pressure%Excavation face stability
文章基于莫尔-库仑屈服准则,通过优化楔形块体的倾角并考虑土体粘聚力的影响,对现有的楔形块+倒棱台的土体破坏模型进行改进,建立了能够得到盾构隧道开挖面处于被动极限平衡状态下支护压力的三维计算模型;同时推导得出了相应的计算公式,并通过优化计算得到了开挖面处被动支护压力最小时楔形块体的倾角及极限支护压力;结合一算例,将所建模型的预测结果与经典的上限解进行了分析对比,验证了其合理性;最后探讨了土体内摩擦角、土体粘聚力、隧道上覆土厚度与隧道开挖面处被动极限压应力间的相互关系。研究结果表明:土体的粘聚力越大,开挖面处被动极限支护压应力越大,两者呈线性关系;土体的内摩擦角越大,被动极限支护压应力越大,且其变化速率也越快;随着隧道上覆土厚度的增加,被动极限支护压应力逐渐增加,且变化速率越来越快,两者之间近似呈指数函数关系。
文章基于莫爾-庫崙屈服準則,通過優化楔形塊體的傾角併攷慮土體粘聚力的影響,對現有的楔形塊+倒稜檯的土體破壞模型進行改進,建立瞭能夠得到盾構隧道開挖麵處于被動極限平衡狀態下支護壓力的三維計算模型;同時推導得齣瞭相應的計算公式,併通過優化計算得到瞭開挖麵處被動支護壓力最小時楔形塊體的傾角及極限支護壓力;結閤一算例,將所建模型的預測結果與經典的上限解進行瞭分析對比,驗證瞭其閤理性;最後探討瞭土體內摩抆角、土體粘聚力、隧道上覆土厚度與隧道開挖麵處被動極限壓應力間的相互關繫。研究結果錶明:土體的粘聚力越大,開挖麵處被動極限支護壓應力越大,兩者呈線性關繫;土體的內摩抆角越大,被動極限支護壓應力越大,且其變化速率也越快;隨著隧道上覆土厚度的增加,被動極限支護壓應力逐漸增加,且變化速率越來越快,兩者之間近似呈指數函數關繫。
문장기우막이-고륜굴복준칙,통과우화설형괴체적경각병고필토체점취력적영향,대현유적설형괴+도릉태적토체파배모형진행개진,건립료능구득도순구수도개알면처우피동겁한평형상태하지호압력적삼유계산모형;동시추도득출료상응적계산공식,병통과우화계산득도료개알면처피동지호압력최소시설형괴체적경각급겁한지호압력;결합일산례,장소건모형적예측결과여경전적상한해진행료분석대비,험증료기합이성;최후탐토료토체내마찰각、토체점취력、수도상복토후도여수도개알면처피동겁한압응력간적상호관계。연구결과표명:토체적점취력월대,개알면처피동겁한지호압응력월대,량자정선성관계;토체적내마찰각월대,피동겁한지호압응력월대,차기변화속솔야월쾌;수착수도상복토후도적증가,피동겁한지호압응력축점증가,차변화속솔월래월쾌,량자지간근사정지수함수관계。
Based on the Mohr-Coulomb yield criteria, the failure model of a wedge block + inverted truncated pyramid is improved by considering the influence of soil cohesion and optimizing the inclined angle of the wedge block, and a three-dimensional model is established to calculate limit support pressure when the excavation face is in the passive limit equilibrium state. Meanwhile, a corresponding formula is deduced to calculate the limit support pressure, and its solution is obtained by optimization analysis. Based on a calculation example, a comparison between the predicted results from the proposed model and the classic upper bound solution is made to verify its rationality. Finally, the relationship among the passive limit pressure, cohesion of the soil, friction angle of the soil, and thickness of the overburden is studied. Results show that there is a linear relationship between the cohesion of the soil and the passive limit support pressure, which means that the greater the cohesion of the soil, the greater the passive limit support pressure; the larger the friction angle of the soil, the greater the passive limit support pressure and the faster its rate of change is; and with an increase of the overburden of the tunnel, the passive limit support pressure increases gradually, and the rate of change becomes faster and faster, which presents an approximate exponential function relationship.