This study presents the relationships between drill bit lifetime and mechanics, drillability and abrasive properties of rocks. Additively, worn-out of bit types were investigated. For that purpose, rock blocks were collected from tunnels. Regression analyses were employed to derive models for estimating the bit lifetime based upon drillability, and mechanical and abrasive properties of the rock. Results indicated that the bit lifetime values decrease with the increases of the uniaxial compressive strength, point load index, Brazilian tensile strength, Schmidt hardness (L-type and N-type) and Cerchar abrasivity index. However, the drill bit lifetimes increased with the increasing of Micro Deval abrasion, Brittleness values, Sievers' J-miniature drill, and excavation volume values. The statistical results showed that the most important parameters on the drill bit lifetimes were uniaxial compressive strength, Schmidt hammer, Sievers’ J-miniature drill, and excavation volume. Furthermore, developed models would be used as guidance for practical applications.

The paper also was investigated the bit wear types and their classification. Two new different bit wear types were investigated including, crack of the bit body and failure of bit rod. The crack of the bit body is a typical for the failure of tool materials. The failure of bit rod is typical for special wear types.

这项研究提出了钻头寿命与岩石力学，可钻性和磨蚀性之间的关系。另外，对钻头类型的磨损进行了研究。为此，从隧道中收集了岩石块。进行了回归分析，以基于可钻性以及岩石的机械和磨蚀特性，得出用于估算钻头寿命的模型。结果表明，随着单轴抗压强度，点载荷指数，巴西抗拉强度，施密特硬度（L型和N型）和Cerchar耐磨性指数的增加，钻头寿命值减小。但是，随着Micro Deval磨损，脆性值，Sievers的J型微型钻头和开挖量值的增加，钻头的使用寿命也随之增加。统计结果表明，影响钻头寿命的最重要参数是单轴抗压强度，施密特锤，Sievers J型微型钻和开挖量。此外，已开发的模型将用作实际应用的指南。

本文还研究了钻头磨损类型及其分类。研究了两种新的不同的钻头磨损类型，包括钻头体的裂纹和钻头杆的损坏。钻头体的裂纹是导致工具材料失效的典型原因。特殊磨损类型的钻头杆故障是典型的。