微型桩整治隧底填充结构裂损病害的原理及效果分析

某隧道进口段仰拱填充结构在施工期出现大量未贯通的"V"字形裂缝。根据隧底填充结构裂损特征,结构现场工程地质条件、水文地质条件、地形地貌及隧道地下水排导系统设计与施工情况,得出作用在仰拱填充结构上的水压力是导致其开裂的主要原因。提出了通过发挥微型桩受拉特征整治水压力作用下隧底填充结构裂损病害的措施。通过数值分析、现场测试和观察得出了微型桩加固能有效减少或抑制仰拱隆起,防止隧道仰拱填充结构的"V"字形裂缝产生和发展。论证了利用微型桩整治水压力作用下隧底填充结构裂损病害的有效性,为类似隧道病害整治提供了参考依据。

Mechanism and Effect Analysis on Micro-pile Treats Tunnel Invert Filling Structure Crack

Invert filling structure of a tunnel in the entrance region appeared a large number of cracks in the construction period. According to the damage characteristics of tunnel bottom filling structure, engineering geological conditions, hydrogeological conditions, topography and tunnel drainage system and so on, the conclusion that water pressure acting on the invert bottom is main reason of the invert filling structure cracks was obtained. The measure was proposed by making use of micro-piles tensile characteristics to treat tunnel bottom filling structure crack disease, which was caused by water pressure acting on the invert bottom. Through numerical analysis, field test and observation, the micro-piles can effectively reduce or inhibit the invert uplift, prevent the "V" shaped crack of invert structure filled generating and developing, which demonstrates that the micro-piles can improve invert stress state and provide the reference for the similar tunnel.