Abstract: Aiming at the problem that immediate support and permanent support are difficult to balance during deep mining,
a random-system time-segmented asynchronous collaborative support technique is proposed. A support system of " initial
rapid support-secondary collaborative reinforcement" is constructed to achieve the balance between early deformation suppression
and overall stability enhancement of surrounding rock. Time-segmented asynchronous collaborative support components are
developed,and their mechanical properties are verified through laboratory pull-out tests. The test results show that the peak load
of the component is 124. 25 kN,and the slip load can reach 96 kN,which is obviously about 3 times superior to that of split set
bolts,and it can quickly suppress the loosening of surrounding rock in the early stage of roadway construction. Based on this
technique,external bolts are quickly arranged for random support,and then internal bolts are collaboratively reinforced with
metal meshes to form a dynamic reinforcement system characterized by " point-surface combination,time-segmented construction,
and asynchronous collaboration". To further evaluate its effectiveness,FLAC3D software is used for numerical simulation.
The results indicate that the collaborative support method optimizes the stress distribution of surrounding rock,makes stress
transmission smoother and wider,significantly reduces the development of plastic zones,and lowers the risk of local damage.
Compared with conventional support,the position of the maximum vertical stress under collaborative support shifts backward to
1. 4 m,the stress peak is gentle,the maximum depth of the plastic failure zone decreases by about 1 m,and the failure range
and degree are both reduced. This technique has been applied in the fractured roadway of a lead-zinc mine through a unique
construction method. Monitoring results show that the cumulative increase in bolt axial force is 1. 34 kN,and the maximum displacements
of the roof,floor,and two sides are stably controlled at 1. 8 mm and 0. 8 mm respectively,indicating that the surrounding rock deformation is effectively restrained. The research demonstrates that the random-system time-segmented asynchronous
collaborative support technique can meet the requirements of both immediate support and permanent support,providing
an efficient and reliable support solution for the stability of deep high-stress roadways.