Mechanical properties and field application of constant resistance energy-absorbing anchor cable

摘要

During the construction of underground engineering projects, it is often confronted with complex conditions such as high stress, extremely soft rock, and strong disturbance, resulting in stress concentration and energy accumulation in the surrounding rock. Due to insufficient elongation and low safety margin, it is difficult for common anchor cables to effectively absorb the energy released from the rock deformation, which often results in the failure of the supporting structure. To this end, a new material constant resistance energy-absorbing anchor cable (CREAC) is developed with high elongation and high energy absorption properties. To study the mechanical and energy absorption properties of the new anchor cable, the static tensile and dynamic impact tests are conducted. The results between CREAC and structural constant resistance and large deformation anchor cable (CRLDC) are compared. In terms of static mechanical properties, the maximum elongation of CREAC is 16.2%. Based on the commonly used cable length of 10 m in the field, the maximum elongation and the energy absorbed by CREAC are 2.21 times and 2.76 times that of CRLDC, with good static deformation and energy absorption capabilities. In terms of dynamics properties, the average single impact deformation of CREAC is reduced by 88.7% compared to CRLDC, and the energy it can absorb is 7.43 times that of CRLDC, showing advantages in impact deformation resistance and energy absorption. The design method of the constant resistance energy-absorbing support is proposed and the field application of CREAC is carried out. The monitoring results confirm that this new material anchor cable can effectively control the deformation of the surrounding rock.