Mechanical Properties of High‐Strength High‐Performance Reinforced Concrete Shaft Lining Structures in Deep Freezing Wells

Abstract

As coal resources must be mined from ever deeper seams, high-strength, high-performance concrete shaft linings are required to resist the load of the soil surrounding the deep freezing well. In order to determine the optimal concrete mix for the unique conditions experienced by such high-strength high-performance reinforced concrete shaft lining (HSHPRCSL) structures in deep freezing wells, an experimental evaluation of scaled HSHPRCSL models was conducted using hydraulic pressure load tests. It was observed that as the specimens ruptured, plastic bending of the circumferential reinforcement occurred along the failure surface, generated by compression-shear failure. These tests determined that HSHPRCSL capacity was most affected by the ultimate concrete uniaxial compressive strength and the thickness-diameter ratio and least affected by the reinforcement ratio. The experimental results were then used to derive fitting equations, which were compared with the results of theoretical expressions derived using the three-parameter strength criterion for the ultimate bearing capacity, stress, radius, and load in the elastic and plastic zones. The proposed theoretical equations yielded results within 8% of the experimentally fitted results. Finally, the finite element analysis method is used to verify the abovementioned results, and all errors are less than 12%, demonstrating reliability for use as a theoretical design basis for deep HSHPRCSL structures.

Experimental Study on Durability of Hybrid Fiber-Reinforced Concrete in Deep Alluvium Frozen Shaft Lining

“…Frozen shaft lining concrete in deep alluvium has been used under a harsh engineering environment for a long time [14][15][16]. In addition to bearing loads, such as high ground pressure and freezing pressure, the built shaft was also faced with problems, such as water seepage, freezing, and thawing, and the erosion of harmful ions in groundwater [17][18][19][20].…”

Research and Application of the Local Differential Freezing Technology in Deep Alluvium

“…Since 1987, more than 200 shafts have been damaged in Huang-Huai and Northeast China, severely threatening the safety of mine production and causing major economic losses. At present, the repair of damaged shaft linings has become an important part of mine construction engineering [1][2][3][4][5]. e problem of water inrush has always been a major problem in the repair work of damaged shaft linings in water-rich areas.…”