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硫酸盐腐蚀是锚索结构长期锚固性能退化的原因之一。为模拟围岩约束条件下硫酸盐对锚索浆体的腐蚀及腐蚀后的锚固受力过程,设计外包钢管圆柱形素水泥浆中置钢绞线短黏结试件并进行长期硫酸盐干湿循环腐蚀,然后通过静力拔出试验观察黏结受力过程,获取黏结滑移曲线,定义锚固特征参数。结果表明:围岩约束作用对腐蚀过程及拔出受力过程产生显著影响,腐蚀引起的物理损伤得以阻止,化学损伤成为主要腐蚀损伤方式;拔出破坏特征为:浆体螺旋肋逐渐被磨平,索体最终被抽出;全程黏结滑移曲线由初期极速上升段、中后期锯齿形上升段及末期快速下降段组成;当围岩变形模量增大时,设计允许滑移、设计强度、极限滑移以及极限强度均随之增大;当浆体腐蚀程度增大时,设计强度、极限滑移以及极限强度随之降低,而设计允许滑移则因浆体模量的退化而随之增大。
Sulfate corrosion is one of the reasons for the long-term anchoring performance degradation of the cable structure. In order to simulate the corrosion of anchorage slurry and the anchoring stress process of sulfate under the confinement of surrounding rock, a short stranded test specimen of steel-lined tubular colloidal cement was designed and subjected to long-term sulfate wet-dry circulation Corrode, and then observe the bond force process through the static pull-out test to obtain the bond slip curve and define the anchoring characteristic parameters. The results show that: the constraint of surrounding rock has a significant effect on the corrosion process and pull-out process, and the physical damage caused by corrosion can be prevented, and the chemical damage becomes the main corrosion damage mode. The pull-out damage characteristics are as follows: , The cable body is finally pulled out; the whole bond slip curve consists of the initial velocity rising section, the middle and late zigzag rising section and the late rapid descending section; when the deformation modulus of the surrounding rock increases, the designed slip, design strength, limit Slippage and ultimate strength increase. When the corrosion degree of slurry increases, the design strength, ultimate slip and ultimate strength decrease. The design allowable slippage increases with the degradation of slurry modulus Big.