Many cases of derailments, train accidents and traffic interruptions due to the slope failure and rockfall have been reported in the past on Konkan Railway trackline because of unstable rock slopes. The authorities installed stability enhancement measures such as wire netting, rock bolting and shotcreting which were found insufficient. The failed geotechnical measures prompted authorities to excavate the unstable slopes. Rock blasting is generally not preferred for the excavation of slopes along the transportation route. Stabilisation and widening of slopes by blasting need closure of the route for a considerable time. Discontinuing traffic on Konkan Railway route was undesirable as it connects two important port cities Mumbai and Mangalore. The paper presents an innovative directional controlled blasting (DCB) technique for excavating three unstable slopes (i.e. cuttings) in hilly terrain without disturbing the traffic. New empirical formulae for small geometry blasting to estimate burden and throw have been developed. A unique sequence of firing and excavation with powder factor varying between 0.04 and 0.39 kg/m 3 irrespective of the actual free face was used for rock blasting. The process controlled the throw of blasted material over the track and resulted in a smooth and stable wall. The slope angle has been changed from 80 to 82° to 45–47° and probability of wedge, planar and toppling failures was eliminated. About 100 such accident-prone slopes (52 km cumulative length, 7% of total route) situated at discrete locations along Konkan Railway route were stabilised using the technique. No incident of rockfall and slope failures along these slopes has been observed after the stabilisation.

中文翻译：

---

沿繁忙运输路线开挖不稳定边坡的创新定向控制爆破技术：以印度康坎铁路为例

过去，康康铁路轨道因岩质边坡不稳定，发生过多起因边坡失稳、落石等原因导致的脱轨、列车事故和交通中断的案例。当局安装了铁丝网、锚杆和喷射混凝土等稳定性增强措施，但发现这些措施不够充分。失败的岩土工程措施促使当局挖掘不稳定的斜坡。沿运输路线开挖边坡时，一般不首选岩石爆破。通过爆破稳定和拓宽斜坡需要关闭路线相当长的时间。由于康坎铁路连接孟买和芒格洛尔这两个重要的港口城市，因此中断交通是不可取的。本文提出了一种创新的定向控制爆破 (DCB) 技术，用于在丘陵地带挖掘三个不稳定的斜坡（即岩屑）而不会干扰交通。开发了新的小几何爆破经验公式来估计负荷和投掷量。一种独特的燃烧和挖掘顺序，粉末系数在 0.04 到 0.39 kg/m 3 之间变化，而与实际的自由面无关，用于岩石爆破。该过程控制了喷砂材料在轨道上的投掷，并形成了光滑稳定的墙壁。倾斜角已从 80° 更改为 82° 到 45-47°，并且消除了楔形、平面和倾倒故障的可能性。大约 100 个此类事故多发斜坡（累计长度 52 公里，位于 Konkan 铁路沿线离散位置的总路线的 7%）使用该技术进行了稳定。在稳定之后，没有观察到沿这些斜坡发生落石和斜坡崩塌事件。