Experimental Study On Seismic Performance Of The Modified Raw-soil Wall

The raw-soil construction has a long history,it has many advantages,such as energy saving and environmental protection,good thermal performance,low cost and so on,until today it is still widely used,especially today more and more people pay attention to problems just like ecological crisis,energy crisis,environmental pollution and so on,people are fond of the raw-soil construction deeply.However,the material of raw-soil construction has many deficiencies,for example,the intensity of the raw-soil material is low,the weight of the structure is big,the durability is poor,because of all of above deficiencies the application of the earth building is limited in practical engineering.In this experiment,in the original raw-soil material mixed cement and cinder composed a new material to improve these shortcomings of the raw-soil construction.Our country is one of the multi-earthquake countries,the seismic activity in many regions of our country are very intense,most of residences in underdevelopment areas are raw-soil buildings,while the investigation found that,the earth buildings generally damaged seriously after the earthquake,this threat the life and property safety of people seriously,therefore,study on the aseismic behavior of the earth building is very necessary.At present,the aseismic structural measures of the earth building is very scanty in our country,the different construction measures are used to the raw-soil wall in this experiment,that the wall was builded with the modified raw-soil material,and conduct the anti-seismic experimental research on the modified raw-soil wall,the main research contents are as follows:In order to study the effect of the steel mesh and 8a line to the seismic behaviors of modified raw-soil wall,three pieces of specimen were designed,include a piece of plain raw-soil wall and two pieces of raw-soil wall which were reinforced by add the 8#line in the vertical direction and wire mesh in the horizontal direction.Vertical loads and low cycle horizontal loads were loaded on specimens,study there specimens on failure mode,hysteretic curve and skeleton curve feature,the horizontal bearing capacity and deformation capacity of the wall.The result show that,the specimens which added line 8#in the longitudinal and laying wire mesh in the transverse could delay the raw-soil wall cracking,improve the ultimate load-carrying capacity,this measure also has some effect on improving the later deformation ability of the raw-soil wall,and improve the energy dissipation capacity of the raw-soil wall.The wall added line 8#in the longitudinal could effectively prevent the wall slip too much.In order to improve the seismic performance of the modified earth wall,the construction measure that add the 8#line in the vertical direction and wire mesh reinforcement in the horizontal direction,and modified adobe were adopted to build the wall.The America MTS system was used to give the low cyclic loading on the wall,at the same time,the constant vertical uniformly distributed load was loaded on the top of the wall,to simulate the strained condition that the wall in the earthquake.The results showed that the root of the earth wall was crushed partly,with the load increasing,cracks widening gradually and extending to the middle continuously.Finally the earth wall destroyed by the penetrating crack.The cohesiveness between the wall and the bottom beam was easily destroyed;more attention should be paid in the construction.The cracking load and ultimate load,even the overall performance of the wall and the deformation capacity and the energy dissipation ability were improved by this measures that put the 8#line in the vertical direction and put wire mesh reinforcement in the horizontal direction markedly.In order to study the seismic performance of the modified raw-soil which reinforced by nylon net and 8#line,two pieces of modified raw-soil which reinforced by nylon net and 8#line and one piece of modified raw-soil without any construction measures were designed,the pseudo static test method was adopted,horizontal low cyclic loading was applied on the specimen,get the measured data such as the load,displacement and hysteretic curve of the wall.The result show that the modif1ed raw-soil wall which reinforced by nylon net and 8#line can delay the wall cracking,the limit load of the wall was increased slightly.The energy dissipation capacity of the wall was improved by adopted this construction measure,meanwhile,the rigidity of the wall decline slowly by this measure.In order to study on the seismic performance of the modified raw-soil which reinforced just by 8#line,three modified raw-soil walls only by 8#line and one modified raw-soil wall without any reinforcement measures were designed.Throw applying horizontal low cyclic loading on the modified raw-soil wall,the testing datum about the bearing capacity,displacement,hysteresis curve of the earth wall were recorded,through these datum to study and analysis about the failure modes,the bearing capacity characteristics,energy dissipation capacity and stiffness degradation capacity of the modified raw-soil wall,some some results can be got,the limit load of the wall was increased and the deformation capacity of the wall was improved by the measure that just add 8#line in the wall,the stiffness degradation of the wall was restrained by this measure.By comparative and analysis results of this experiment,it is show that,the structural measures which was used in the wall,can delay the wall crack,improve the ultimate bearing capacity of the wall,improve the wall deformation ability,at the same time,it also have some effect on improving the energy dissipation ability of the wall,so as to absorb more energy in the earthquake.The results of this study provides a scientific basis for the modified raw-soil wall is used in the future,lay the foundation for the further study about the earth building in the future.