摘要
采用直径52cm的土压平衡式模型盾构机进行盾构掘进的室内模型试验。通过在试验隧道上方及两侧地层预先布置水平和竖直方向光纤光栅应变计,测试盾构掘进过程中地层应变分布及变化情况。测试结果表明:盾构隧道开挖后,隧道上方地层,尤其是拱顶附近,在水平方向和竖直方向均出现较大拉应变增量,该区域为盾构隧道掘进主要扰动区,主要原因是盾尾地层临空面的出现;同时,由于隧道开挖引起应力重分布,使隧道两侧竖直(压)应变有所增加。试验揭示了土压平衡式盾构掘进过程中地层应变分布及其变化规律,对于研究土压平衡盾构掘进对周围地层的扰动具有积极意义。
The indoor model test of shield driving was conducted with a Ф52 cm earth-pressure-balanced （EPB） model shield machine. Fiber grating strain gauges were pre-embedded in the ground in horizontal and vertical directions at the top and on both sides of the test tunnel. These gauges monitored the ground strain field and it＇ s variation with EPB shield driving. The test results show as follows： There occur great increments of tension strains in horizontal and vertical directions above the tunnel during tunnel excavation, especially near the vault; the above region is the main disturbed region, which appears as the result of emergence of free faces in the shield machine tail ground; the vertical compression strains on both sides of the tunnel increase due to stress redistribution caused by tunnel excavation. The test reveals the law of ground strain distribution and variation with shield driving, thus providing references to research of ground disturbances induced by the EPB shield machine.
出处
《铁道学报》
EI
CAS
CSCD
北大核心
2013年第5期85-89,共5页
Journal of the China Railway Society
基金
国家自然科学基金(51278422)
国家重点基础研究发展计划(973计划)(2010CB732105)
国家科技支撑计划(2012BAG05B00)
四川省青年科技计划(2012JQ0021)
中央高校基本科研业务费专项资金(SWJTU11ZT33)
关键词
土压平衡盾构
地层应变
模型试验
光纤光栅
earth-pressure-balanced（EPB） shield
ground strain
model test
fiber grating
