Experimental Research And Numerical Simulation On Bam-boo Reinforced Cement-soil Retaining Wall

The soil-cement retaining wall which are inserted by small size-section steelor steel bar is rising in recent years, because the soil-cement gravity retainingwall is too thick and the tensile strength of soil-cement is too low. The feasibili-ty of substituting bamboo reinforcement for small size-section steel and steel barto strengthen plain soil-cement retaining wall is studied since the low-cost bam-boo has excellent mechanical properties and abundant resources.Based on the idea,the paper conducts the pilot study of bamboo reinforcedsoil-cement retaining wall:The mechanical parameters of bamboo reinforcedcement-soil are obtained based on the tensile test and the bond strength test,thenthe bearing capacity of beam is discussed based on the bending test of modelbeam.In addition,the formulas to calculate the bending bearing capacity and thebending stiffnes of beam are derived.On the one hand, the bending experiment ofbamboo reinforced cement-soil beam is simulated by abaqus, on the otherhand,the working performance of plain soil-cement wall and bamboo rein-forced wall are compared in practical engineering.Furthermore,the effects ofbamboo reinforcement ratio,bamboo reinforcement position.etc on working per-formance of bamboo reinforced cement-soil wall are discussed.Finally, the de-sign procedures and engineering application of bamboo reinforced soil-cementretaining wall are disused.The results show that bamboo reinforcement can be used as reinforcement tostrengthen the plain soil-cement wall since the tensile strength of bamboo reachs163MPa.The bond strength of the bamboo reinforcements increases obviouslyby treating with sand and the bond strength corresponds to the level of rein-forced concrete when the cement content is above20%.The bearing capacity ofplain soil-cement wall increases in different degrees by inserting bamboo rein-forcements:The improving multiple of shear-compression failure beam is1.5~1.62;when the beams occur bending failure,the maximum improving mul-tiple of under-reinforced beam is0.493, the improving multiple of ba-lanced-reinforced beam and over-reinforced beam is5.51～5.96.Forshear-compression failure beam,the improving multiple is small and the bearing capacity of beam increase less obviously by increasing reinforcement ratio.Forbending failure beam, the bearing capacity of beam increases with increasingreinforcement ratio,but the improvement of bearing capacity is less obviouswhen the reinforcement ratio is too high.The formulas to calculate the bearingcapacity,bending stiffnes,balanced reinforcement ratio, extended length of bam-boo.etc are derived,it proves that the formulas are reasonable.The appropriatereinforcement ratio of beam lies between0.467%~0.654%.When theplain soil-cement wall is insered by bamboo reinforcements, the excavationdepth increases and the maximum horizontal displace-ment,tensile stress,pressure stress of wall reduce. In addition, the maximum ho-rizontal displacement and pressure stress of cement-soil wall reduce more sig-nificantly with increasing the excavation depth,but the effect is not obviouswhen the compressive zone of wall are insered by bamboo reinforcements.