盾构隧道纵缝接头变形可恢复性足尺试验研究

Full-scale tests on deformation recoverability of longitudinal joints of shield tunnel

进行了盾构隧道拱顶双缝接头和拱腰单缝接头的原型足尺试验,探究两类接头在隧道上方堆载作用下的变形发展规律、以及卸载和土体微扰动注浆条件下的变形可恢复性。试验结果表明:随着地表堆载增大,接头张开变形呈非线性发展;超载引起的变形可以通过卸载得到部分恢复,既有变形越小,恢复效果越好;注浆作用下,拱顶接头的变形恢复效果较拱腰接头更为显著。

A series of full-scale tests are conducted on the two-seam longitudinal joint at the shield tunnel crown and one-seam longitudinal joint at the shield tunnel waist,aiming to explore the deformation development laws of these two joints under the surcharge above the tunnel and the deformation recoverability under the conditions of unloading and soil micro-disturbance grouting.The test results show that the joint opening develops nonlinearly with the increase of the surcharge load.The deformation caused by the surcharge can be partially recovered by unloading.The smaller the deformation,the better the recovery effects.Under the action of grouting,the deformation recovery effects of the joints at the tunnel crown are better than those of the joints at the tunnel waist.