磨料水射流旋转切割岩石深度计算模型

针对地下洞库结构防护设计，需对洞库围岩实施人工致裂，从而在围岩中构建人工裂隙群以达到抗爆消波的目的，提出利用环形磨料水射流切割围岩施工方法。根据磨料颗粒去除非岩石材料体积模型，推导了磨料粒子对岩石的体积去除量与磨料速度关系模型；基于磨料射流切口形状假设了环形磨料射流切割深度估算模型，并与已有数据进行对比验证了模型的有效性；定义磨料射流在外流场的流量衰减系数，提出了磨料射流岩石极限切割深度计算方法，通过算例分析了特定工况下磨料水射流切割砂岩及花岗岩的理想极限深度，得到磨料水射流对岩石的切割半径满足围岩人工割缝半径目标。研究表明:磨料水射流对花岗岩的制缝深度约为切割砂岩的55.7%；使用磨料水射流进行围岩割缝在工程应用中具备施工可行性。

Model of Calculating Depthin Rock by Annularly Cutting with Abrasive Water Jet

In view of the structural protection design of underground caverns, it is necessary to artificially fracture the surrounding rocks of the cavern, so as to construct artificial fracture groups in the surrounding rocks to resist explosion and eliminate waves. A method to cut surrounding rocks with annular abrasive water jet was proposed in this paper. According to the volume model of non-rock materials removed by abrasive particles, a model reflecting the relationship between the volume of removed rocks by abrasive particles and the abrasive velocity was established; a model for estimating the cutting depth of the annular abrasive jet was proposed based on the shape of the abrasive jet incision, and the validity of the model was verified by comparison with the existing data; the calculation method of the limit cutting depth of the abrasive jet was proposed according to the definition of flow attenuation coefficient of the abrasive jet in the external flow field. The ideal limit cutting depth of sandstone and granite by abrasive water jet cutting under specific working conditions was analyzed based on calculation examples, and it was found that the cutting radius of the rock by the abrasive water jet accords with the artificial cutting radius of surrounding rocks. The research shows that the cutting depth of granite by the abrasive water jet is about 55.7% of that of sandstone; it is feasible to cut surrounding rocks with the abrasive water jet in engineering applications.