We investigated bending moment resistance under diagonal compression load of comer doweled joints with plywood members. Joint members were made of ll-ply hardwood plywood of 19 mm thickness. Dowels were fabricated of ...We investigated bending moment resistance under diagonal compression load of comer doweled joints with plywood members. Joint members were made of ll-ply hardwood plywood of 19 mm thickness. Dowels were fabricated of Beech and Hornbeam species. Their diameters （6, 8 and 10 mm） and depths of penetration （9, 13 and 17 ram） in joint members were chosen variables in our experiment. By increasing the connector＇s diameter from 6 to 8 mm, the bending moment resistance under diagonal compressive load was increased, while it decreased when the diameter was increased from 8 to 10 mm. The bending moment re- sistance under diagonal compressive load was increased by increasing the dowel＇s depth of penetration. Joints made with dowels of Beech had higher resistance than dowels of Hornbeam. Highest resisting moment （45.18 N.m） was recorded for joints assembled with 8 mm Beech dowels penetrating 17 mm into joint members Lowest resisting moment （13.35 N.m） was recorded for joints assembled with 6 mm Hornbeam dowels and penetrating 9 mm into joint members.展开更多
扩大头锚索因具有抗拔承载力大、支护效率高等优点在岩土工程中应用广泛,而注浆段落的长度和自由段保护套管的类型将对锚索受力变形特性产生影响。为此,依托实际工程开展了锚固段注浆+PE波纹管(设计方案)、全长注浆+聚乙烯(polyethylene...扩大头锚索因具有抗拔承载力大、支护效率高等优点在岩土工程中应用广泛,而注浆段落的长度和自由段保护套管的类型将对锚索受力变形特性产生影响。为此,依托实际工程开展了锚固段注浆+PE波纹管(设计方案)、全长注浆+聚乙烯(polyethylene, PE)波纹管(实际施工常用方案)、锚固段注浆+高密度聚乙烯(high density polyethylen, HDPE)套管、全长注浆+HDPE套管等四种不同工况扩大头锚索的现场拉拔试验,对比分析了不同工况下锚索的拉拔荷载-位移(Q-s)曲线、荷载-弹性位移(Q-se)曲线与荷载-塑性位移(Q-sp)曲线、自由段伸长量比例、刚度系数等受力变形特征。试验结果表明,相同注浆长度条件下,采用HDPE套管相比PE波纹管能够更好地发挥对自由段的隔离保护作用,保证自由段的变形性能;而采用相同套管类型时,注浆长度的增加会导致自由段伸长量值的减小,并会增大锚索刚度系数。在试验研究的基础上,提出现场锚索施工采用锚固段注浆+HDPE套管或全长注浆+HDPE套管的建议方案,从而保证锚索受力变形性能均达到设计预期。展开更多
文摘We investigated bending moment resistance under diagonal compression load of comer doweled joints with plywood members. Joint members were made of ll-ply hardwood plywood of 19 mm thickness. Dowels were fabricated of Beech and Hornbeam species. Their diameters （6, 8 and 10 mm） and depths of penetration （9, 13 and 17 ram） in joint members were chosen variables in our experiment. By increasing the connector＇s diameter from 6 to 8 mm, the bending moment resistance under diagonal compressive load was increased, while it decreased when the diameter was increased from 8 to 10 mm. The bending moment re- sistance under diagonal compressive load was increased by increasing the dowel＇s depth of penetration. Joints made with dowels of Beech had higher resistance than dowels of Hornbeam. Highest resisting moment （45.18 N.m） was recorded for joints assembled with 8 mm Beech dowels penetrating 17 mm into joint members Lowest resisting moment （13.35 N.m） was recorded for joints assembled with 6 mm Hornbeam dowels and penetrating 9 mm into joint members.
文摘扩大头锚索因具有抗拔承载力大、支护效率高等优点在岩土工程中应用广泛,而注浆段落的长度和自由段保护套管的类型将对锚索受力变形特性产生影响。为此,依托实际工程开展了锚固段注浆+PE波纹管(设计方案)、全长注浆+聚乙烯(polyethylene, PE)波纹管(实际施工常用方案)、锚固段注浆+高密度聚乙烯(high density polyethylen, HDPE)套管、全长注浆+HDPE套管等四种不同工况扩大头锚索的现场拉拔试验,对比分析了不同工况下锚索的拉拔荷载-位移(Q-s)曲线、荷载-弹性位移(Q-se)曲线与荷载-塑性位移(Q-sp)曲线、自由段伸长量比例、刚度系数等受力变形特征。试验结果表明,相同注浆长度条件下,采用HDPE套管相比PE波纹管能够更好地发挥对自由段的隔离保护作用,保证自由段的变形性能;而采用相同套管类型时,注浆长度的增加会导致自由段伸长量值的减小,并会增大锚索刚度系数。在试验研究的基础上,提出现场锚索施工采用锚固段注浆+HDPE套管或全长注浆+HDPE套管的建议方案,从而保证锚索受力变形性能均达到设计预期。
