三峡永久船闸中隔墩裂缝原因分析

A Cause Analysis on Cracks of Intermediate Partition Piers for Permanent Shiplocks of the Three-Gorges Project

分析中隔墩顶面砼上出现的裂缝，是岩体裂缝、砼温差、砼干缩等因素的综合反映，而岩体裂缝的主要原因是开挖卸荷和岩体中存在不利的地质结构面，其次是锚固不及时，开挖爆破以及端头锚引起的附加拉应力等,开挖停止后，未产生新的裂缝，岩体中的裂缝扩展至收敛状，裂缝尚未对中隔墩造成严重的损伤，中隔墩仍处于稳定状态．

Cracks were found on the top concrete surface of the intermediate partition piers for thepermanent shiplocks of the Three-Gorges Project,which is deemed to be a complex reflection of suchfactors as fractured rock masses, concrete thermal difference, concrete shrinkage and the like. Fissureson the rock masses are primarily caused by unloading during the period of excavation and some adversegeo-structural planes therein, and secondarily by delayed rock-bolting, cxcavation, blasting practiceand additional tensile stress by the end anchors. However, after excavation practice ceased, no freshcracks were exposed there to, and development of the existing fissures on rock masses was in a statusof convergence, which indicates the existing cracks have not caused any serious damage to the partitionpiers which are still in a state of stability.