CAJ | 학술논문

在膨胀土地基中进行隧道对群桩影响的三维离心模型试验研究，目标地层损失比为2%，着重研究引起的地基沉降槽、桩的附加沉降、附加弯矩、轴力的变化规律。试验得出：隧道开挖沉降槽空间效应明显；隧道开挖从-0.75D 至1.25D时，桩附加沉降呈线性增长，隧道开挖至1.25D以后，桩依然沉降明显。前桩与后桩沉降值不同，桩帽会出现倾斜；前桩上部出现负附加弯矩而下部出现正附加弯矩，而后桩仅在下部出现正附加弯矩；前桩附加弯矩最大值出现在隧道轴线附近，且比后桩附加弯矩大得多；前桩附加轴力随着隧道的开挖而增加，且每步最大值在隧道轴线附近。后桩的轴力也随隧道的开挖而增加，但每步最大值出现在桩顶附近。
재팽창토지기중진행수도대군장영향적삼유리심모형시험연구，목표지층손실비위2%，착중연구인기적지기침강조、장적부가침강、부가만구、축력적변화규률。시험득출：수도개알침강조공간효응명현；수도개알종-0.75D 지1.25D시，장부가침강정선성증장，수도개알지1.25D이후，장의연침강명현。전장여후장침강치불동，장모회출현경사；전장상부출현부부가만구이하부출현정부가만구，이후장부재하부출현정부가만구；전장부가만구최대치출현재수도축선부근，차비후장부가만구대득다；전장부가축력수착수도적개알이증가，차매보최대치재수도축선부근。후장적축력야수수도적개알이증가，단매보최대치출현재장정부근。
A three-dimensional centrifuge model test was carried out to investigate tunnelling effects on pile group in expansive clay. A volume loss of 2%was controlled. During the test, ground settlement trough, additional settlement, additional bending moment and axial force of pile due to tunnelling were monitored. The results show that ground settlement troughs are affected obviously by the distance between the centre axis of pile group and tunnel face. The additional settlement of pile shows linear growth with the tunnel excavation from-0.75D to 1.25D;and it continues to settle even when the tunnel excavation reaches 1.25D away. The settlements of front piles and behind piles are different;and the pile cap tilts. Positive additional bending moment presents at the top of front pile while negative bending moment presents at the bottom. However, only positive additional bending moment occurs at the bottom for behind pile. Moreover, the maximum additional bending moment of the front pile occurs near the axis of tunnel;and it is much bigger than that of the behind pile. The additional axial force of the front pile increases with the tunnel construction and reaches maximum near the axis of tunnel. The additional axial force of the behind pile increases too;but it reaches maximum near the top of pile.