The study examined the two-anchor system of Extension-Type Bamboo/Rebar Tension-Pressure(EBTP)anchor rods in earthen sites.Indoor two-anchor digital image correlation(DIC)pullout tests with anchor spacing of 0.3 m and 0.6 m were conducted to clarify the load-displacement relationship and typical failure modes.Based on the characteristics of anchor slip failure modes,a 2D finite element method(FEM)was proposed for the two-anchor system.The slurry/soil interface under compression and rod/pulp interface in tension were simulated using the contact pairs and nonlinear springs,respectively.Experimental results indicated that,at 0.3 m spacing,horizontal cracking along the rammed earth layer was the primary failure mode,while at 0.6 m spacing,a conical cracking pattern emerged with a transition between tension and compression at an angle of 30°～45°,yielding a maximum crack radius of approximate-ly 24 cm at the soil top surface.The bearing capacity decreased by approximately 7％at 0.3 m spacing compared to 0.6 m spacing.The simulation analysis illustrates that anchor spacing has a significant influ-ence on the group anchor effect.For one thing,when the spacing exceeds 0.6 m,the group anchor effect is more limited,which is consistent with experimental results.For another,the depth of the expansion body demonstrates an approximately linear correlation with the ultimate bearing capacity of the anchor.There-fore,as anchor length increases,the bearing capacity initially increases sharply,followed by a more mod-erate increase.Although the group anchor effect gradually strengthens,the increment in bearing capacity due to increased anchor length outweighs the loss caused by the group anchor effect.These findings pro-vide valuable insights for the design of EBTP anchor groups in earthen sites.The simulation methodology in this study can be used to predict and optimize anchorage design parameters for anchoring works at earth-en sites.
关键词
土遗址锚固/两锚同步拉拔试验/数值模拟/荷载-位移关系/群锚效应
Key words
anchorage of earthen sites/synchronous pullout test of two-anchor system/numerical simulation/load-displacement relationship/group anchor effect
维普
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