锚喷结构中钢锚杆锈蚀量的估计分析

ESTIMATION OF THE AMOUNT OF STEEL BOLT CORROSION IN SHOTCRETING AND BOLTING STRUCTURE

根据采矿工程中锚杆锈蚀问题，提出了地下环境场下钢锚杆开始锈蚀时间的确定方法．同时依据腐蚀电化学原理，建立了预测钢锚杆锈蚀量的数学模型，导出了两类环境锚杆锈蚀开裂前和开裂后的锈蚀量计算公式．这里考虑了环境碳化、相对湿度和水膜对氧化吸收能力的影响．讨论了锚杆锈蚀量与各影响因素的关系，得出了锈蚀量随时间、锚杆直径的增大而增加，且锈蚀时间越长，钢锚杆直径影响越大等重要结论．

A method is proposed for determining the initial time of corrosion of steel bolts in underground environment based on investigation of corrosion of steel bolts in many mining projects. In the principles of electrochemical corrosion a mathematical model for prediction of bolts corrosion was established. Formulae were derived for calculating the amount of corrosion before and after cracking of the sprayed layer under two types of underground environment. Environmental carbonization, relative humidity, the effect of water film on absorption of oxygen were taken into consideration. The influence of all the factors on the amount of corrosion were discussed. Important conclusions were drawn. The amount of corrosion increases with the increase of time and the diameter of the steel bolts. The longer the time, the greater the influence of the bolt diameter.