The Study On Seismic Behavior And Design Method Of Reactive Power Concrete Shear Walls

According to current high-rise structures having commonly existed problems with huge structure weight and big section dimension of vertical member, based on RPC(reactive powder concrete) materials’ excellent performance, this paper made experimental and theoretical researches on RPC shear wall seismic performance and design methods, and analyzed RPC shear wall’s possibility on the appliance in super high-rise structures. The main researches are:(1) It systematically summarized new material RPC and RPC component 、structure’ research status, analyzed RPC’s appliance in practical project, made detailed induction of concrete shear walls’ research course, combined high-rise structure characters, demonstrates RPC shear wall’s feasibility in theory.(2) Having made low cyclic loading experiments of three RPC shear walls with different height-width ratios, the effect of height-width ratio on the seismic behavior such as failure mode, bearing capacity, hysteretic loops,characteristic of energy dissipation and rigidity degeneration were studied. The experiment result shows: RPC shear wall has high bearing capacity, height-width ratio has important influence on RPC shear wall’s failure mode, the RPC shear walls having height-width ratio as 1, 1.5, 2 has shear failure、flexural-shear failure and flexural failure correspondingly. With the increase of height-width ratio, specimen hysteretic curve pinch phenomenon fades, specimen energy consumption capacity increases, energy consumption increases 3.9 times, the shear wall displacement ductility factor with height-width as 2 is more than 3. RPC shear wall failure mode is basically similar with common concrete and high performance concrete shear wall, but cracks are more widely distributed with larger number and density.(3) Employing finite element analysis program Open Sees and multi-layer shell, it made numerical simulation of RPC shear wall specimen’s whole loading process. The numerical simulation result matched experimental results well, thus it chose height-width ratio, axial compression ratio, the reinforcement ratio of hidden column, the reinforcement ratio of distribution bars etc as variables, made parameter analysis of RPC shear wall, and mainly analyzed the rules of parameters’ s influence on its bearing capacity and ductility. These are the conclusions: When the height-width ration of RPC shear wall discussed is more than 2, the ductility requirement of displacement ductility index less than 2 can be guaranteed; axial compression ratio’s influences on bearing capacity and displacement ductility are obvious. With the increase of axial compression ratio, bearing capacity increases and ductility greatly decreases at the same time; the increase of the reinforcement ratio of hidden column can greatly improve RPC shear wall’s bearing capacity, but when the reinforcement ratio is more than 4.24%, the ductility of component begins to reduce; the reinforcement ratio of distribution bars has little influence on RPC shear wall bearing capacity and ductility.(4) Based on the experimental research, it makes researches on RPC shear wall normal section and inclined section bearing capacity computational model、crack load model, derives the bending load of the normal section and crack load formulas, made researches on shear wall inclined section bearing capacity by using Softened Truss Theory and Chinese、 American、European regulations’ common concrete shear wall formulas, which can provide references for programs. Checked with the experiments, it built restoring force model applicable to RPC shear wall, gave formulas of skeleton curves to degenerated three-linearity model and every key points, and analyzed RPC shear wall’s hysteresis rule and unloading stiffness.(5) On the basis of common concrete bending damage shear wall experimental research data, it compared the error between calculation data and experimental data of ultimate displacement under different plastic hinge calculation formula.The result shows that ultimate displacement deviation from NZ plastic hinge calculation formula is the least and the calculation formula has wide range of application. Deducing bending damage shear wall axial compression ratio calculation formula from theory, based upon NZ code plastic hinge calculation formula, on the basis of the definition of displacement ductility, it set up the relationship between axial compression ratio and displacement ductility, made parameter analysis of shear wall axial compression ratio limit’s influence factor, gave design suggestion of ordinary concrete shear wall axial compression ratio limits. Employing experimental and theoretical methods, RPC shear wall axial compression ratio limits is studied. Aiming at displacement ductility factor not less than 3, it gave suggestions on RPC shear wall axial compression ratio limits.(6) By collecting 110 shear-failured shear wall inclined section bearing capacity experimental data, it got shear wall inclined bearing capacity calculation model uncertainty statistical parameter and probability distribution type. Combining geometric statistical parameter and material statistical parameter, it got current regulations’ shear wall inclined bearing capacity statistical parameter’s computational formula and probability distribution type. It combined loading effect required by regulations and programmed reliability index computation program,thus making parameter analysis of shear wall inclined bearing capacity reliable degree level and reliability index factors. The results show: the reliability index can not meet the demand of target reliability index as 3.7. The factors which greatly influence reliability index are wind load and dead load effect ratio, live load and dead load effect ratio and the types of distributed reinforcement, but the variety of shear span ratio, axial pressure, the reinforcement ratio of horizontal bars, concrete strength have little influence on reliability index. To guarantee shear wall inclined bearing capacity reliability degree met the demands of standard, and it modified current calculation formula. The average reliability index of calculation formula modified is 3.849 and meets the demand that the target reliable index is 3.7.(7) On the basis of RPC materials and RPC shear wall’s researches, taking current common concrete super high-rise tube-in-tube structure as background, selecting a RPC super high-rise structure of the same height, it made comparative researches on dynamic characteristics, deadweight, comfort degree, seismic performance. The result shows: compliance with exiting codes, the whole deadweight of RPC super high-rise structure reduces by 31.3% than common concrete structure, column concrete decreases by 54%, shear wall concrete reduces by 50%, floor concrete reduces by 9.4%. The reduction of deadweight makes the earthquake effect of RPC super high structure reduces by 25.59%( X direction) and 25.72%(Y direction). At the same time, RPC excellent mechanical property is more competitive in improving structure operational life span, reducing maintenance fare than common concrete structure.