新型外爪式钢管土钉受力性能研究

Study on the mechanical properties of anew type of external claw steel tubular soil nailing

研发了一种外爪式钢管土钉,对黏性土中外爪伸出长度为20 cm,25 cm,30 cm的外爪式土钉与普通钢管土钉进行抗拉性能对比试验,分析了其受力性能的差异以及外爪长度对土钉受力性能的影响。对所研究的外爪式土钉与普通钢管土钉在基坑开挖后进行土钉墙整体圆弧滑动稳定性计算,得到各工况下土钉墙的稳定性安全系数的差异。分析结果表明,在此次试验的20 cm~30 cm外爪长度的范围内,外爪式土钉极限抗拔承载力均高于相同尺寸的普通钢管土钉,且土钉抗拔力随外爪长度的增加而增大。随着外爪长度的增加,土钉支护的整体稳定安全系数也随之增大。

A kind of external claw type soil nailing was developed.The tensile properties of the external claw type soil nailing with the external claw extending length of 20 cm,25 cm and 30 cm were compared with that of the common steel pipe soil nailing.The difference of the mechanical properties and the influence of the external claw length on the mechanical properties of the soil nailing were analyzed.After the excavation of foundation pit,the circular sliding stability of soil nailing wall is calculated,and the difference of stability safety factor of soil nailing wall under different working conditions is obtained.The results show that in the range of 20 cm~30 cm external claw length,the ultimate pull-out bearing capacity of external claw soil nailing is higher than that of common steel pipe soil nailing of the same size,and the pull-out capacity of soil nailing increases with the increase of external claw length.With the increase of the length of the external claw,the overall stability safety factor of the soil nail support is increased.