Side spalling/skin failure occurs due to the high-induced stress in underground structures. In such cases, rock bolting or other support systems are being used to control the skin failure or spalling of the pillar. The nature of these support systems is passive, which acts during the deformation. These support systems restrict the displacement considerably of the side/or roof surface of the excavation. Ultimately, it improves the stability of the structure because of the increment in residual strength of rock mass. It is noted that these passive support systems give very low confinement in the range of 0–0.015 MPa at the onset of failure. As the level of confinement will be very low and dependent with progress of failure, triaxial test was not found practically suitable. Thus, an alternative procedure of testing has been proposed. In the procedure, sides of sample have been restricted little bit by using adhesive tape. It provides the limited boundness on the lateral direction (LBLD) of rock specimen. The uniaxial compression strength (UCS) test has been performed on 30 numbers of cylindrical rock specimens using the servo-controlled stiff testing machine. Specifically, two rock types (medium-coarse–grained and coarse-grained rocks) were studied in terms of stress–strain behaviour so that a full residual strength envelope for each specimen was obtained. This study reveals that the residual strength of limited confined rock specimens has been significantly increased as compared to unconfined rock for both groups of rock types. The average residual strength of LBLD specimens of fine-grained rock and medium coarse-grained rock has been increased around 12 times, and five times as compared to unconfined rock, respectively. The average peak strength of LBLD rock specimens has been increased in the range of 30.5 to 48.6% for coarse-grained rock. The results of this study have been presented in terms of peak strength, residual strength and Young’s modulus of rock, and the post-peak failure behaviour of rock specimens was also critically analysed through a stress–strain curve.

由于地下结构中的高诱导应力，会发生侧面剥落/表皮破坏。在这种情况下，使用岩石锚杆或其他支撑系统来控制支柱的表皮破坏或剥落。这些支撑系统的性质是被动的，在变形过程中起作用。这些支撑系统极大地限制了挖掘的侧面/或顶部表面的位移。最终，由于岩体残余强度的增加，提高了结构的稳定性。值得注意的是，这些被动支撑系统在发生故障时提供 0-0.015 MPa 范围内的非常低的限制。由于限制水平非常低并且与失效的进展有关，因此三轴试验实际上并不合适。因此，提出了另一种测试程序。在此过程中，使用胶带对样品的侧面进行了一些限制。它提供了岩石样本横向（LBLD）的有限边界。使用伺服控制刚性试验机对30个圆柱形岩石试件进行了单轴抗压强度（UCS ）试验。具体来说，研究了两种岩石类型（中粗粒岩石和粗粒岩石）的应力应变行为，以便获得每个样本的完整残余强度包络线。这项研究表明，对于两组岩石类型来说，与无约束岩石相比，有限约束岩石样本的剩余强度显着增加。细粒岩石和中粗粒岩石的LBLD试件的平均残余强度比无约束岩石分别提高了约12倍和5倍。对于粗粒岩石，LBLD 岩石样本的平均峰值强度增加了 30.5% 至 48.6%。这项研究的结果以岩石的峰值强度、残余强度和杨氏模量的形式呈现，并且还通过应力-应变曲线对岩石样本的峰值后破坏行为进行了严格的分析。