The earthquake disaster is one of serious natural disasters which the humanity faces. The earthquake has the burst characteristics characteristic, until now might the forecast very be still low. The strong earthquake often creates the person and the property heavy loss. Our country is the earthquake to send the country, needs to consider the earthquake resistance garrisons vast in territory, therefore the research structure earthquake resistance performance haste full necessity in our country.

Our country modern earthquake resistance design theory is starts from the 50's, develops in under the international earthquake resistance theory impetus, and gradually has formed own characteristic. In accumulated the suitable research results and in the experience foundation, formulated 74 one after another, 78, 89 has been standard and the new revision 2,001 earthquake resistances designs standard(GB5001122001) the standard design building earthquake resistance ability comparatively 89 standards may enhance 10% according to 2001 ~15%, its technical content achieved the international advanced level. But as a result of the state economy strength limit, the safe establishment is still lower than US and so on the developed country.

Must want better to carry out the standard to have to be clear about the earthquake resistance standard formulation the basic thought, is clear about the earthquake resistance design the basic principle. Under emphatically does from following several aspects elaborated.

1 under the earthquake function, pursues the structure the intensity certainly not to be possible constantly to take, the structure ductility is count for much.

The earthquake divides into slightly shakes, center shakes with the big quake. So-called slightly shakes refers is often meets the probability which the earthquake,50 years appears probably is 63%, Center shakes is refers to the probability which 50 years appears approximately is 10%. But the big quake refers is rarely meets the probability which theearthquake,50 years appears is 2% ~ 3% .Regarding fortuitous and the random very big earthquake load, needs to want to cause the structural strength certainly to be bigger than the structure to respond that, nearly is not impossible, moreover is extremely uneconomical. Is withstood the sacrifice the society the ability and the economical restriction factor, we only can embark from the probability angle, enable the structure safely normally to play the role under the certain probability guarantee. This had decided the earthquake resistance design basic principle, "slightly shakes not badly, center shakes may repair, big quake which namely usually said in our country not but actually". In "slightly shakes" under the function, the request structure is not damaged or does not have to repair still may continue to use. Said from the structure earthquake resistance analysis angle that, is requests the structure in "slightly to shake" under the function to maintain the accurate elastic reaction condition, but does not enter causes the building severance to use and to have the inelasticity reactive state which the non- structural unit destroys; Simultaneously the structure lateral deformation should control in the reasonable limit scope, the goal is enable the structure to have the enough anti-side force rigidity.

Middle shakes probably is equal garrisons the intensity earthquake to us, when shakes the function the bitter experience to the center, the structure may have the certain degree the damage, or still could not continue after the repair after the repair to use. Said from the economical angle that, the maintenance cost cannot too be high.

To has the probability minimum rarely meets the big quake ("big quake” intensity to garrison about intensity to be approximately higher than). The request works as the structure when the bitter experience” the big quake" the function, should not collapse the serious destruction which or occur endangers life.

This kind of earthquake resistance garrisons the goal is extremely economical reasonable. Because of earthquake occurrence too accidentally, supposing we pursue the structure the intensity to guarantee constantly shakes even is under the big quake function the structure is not bad, this will be able to cause the extremely massive materials in the major part time, even in entire life span in all will be at cannot fully play the role the condition, will do this will be wise.

Under the above principle of design instruction, the request structure is in this kind of kind of condition: When slightly shakes approaches, should guarantee all structural unit when the resistance earthquake action, has the enough intensity, causes its basically is at the elastic condition. And through calculate slightly shakes under the function the elastic displacement to guarantee together the structure is not bad. Is at this stage the structural unit not to be able to have the obvious non-linear distortion, also does not need to need to take the special structure measure. Shakes under the function in the center, the structure certain essential spots surpass the elastic strength, enters submits, has a bigger distortion, achieved the non-linear stage, by now, we on specially proposed the ductility request(the ductility refers when the earthquake forces the structure has the bigger non-linear distortion, the structure still can maintain its initial intensity the ability, was the structure surpasses the elastic stage the distortion ability, it is the structure earthquake resistance ability strong and the weak symbol. It and depends on including the withstanding enormous distortion ability stagnates the characteristic absorbed energy the ability, it is resists earthquakes middle the design a count for much characteristic). Middle shakes approaches, because the structure has the inelastic characteristic, certain essential spots surpass its elastic strength, enters the plastic state. Because it has the certain ductility, its non-linearity can undertake the plastic deformation, enables it to consume and to absorb the earthquake energy in the distortion. The price is possibly causes a wider crack, the concrete epidermis to get up the shell, falls off, possibly has the certain remaining distortion, but as fordoes not cause the safe expiration, achieved shakes may repair garrisons the goal. Is at this stage the structure, can set the corresponding request to the ductility, but the ductility must depend on the careful design the detail structure measure to guarantee. When the big quake approaches, the structure non-linearity distorts extremely in a big way, also possibly has the destruction which cannot be repaired. Is at this stage the structure to need through to calculate its ball plastic deformation to guarantee the structure doesn’t send collapses?

Therefore, usually we only need according to young to shake the function effect and other load effects basic combinations calculate component section earthquake resistance supporting capacity and structure elastic deformation. But center shakes the function effect to need the structure to depend on the certain plastic deformation ability (namely ductility) to resist. Therefore the structure ductility to the construction earthquake resistance is extremely important.

2 earthquake force step-downs ratio size has decided the design earthquake force value size, thus has decided to the ductility request size

States from on, uses in the supporting capacity design earthquake function to be allowed to take slightly shakes the level, when a bigger earthquake approaches, then depends on the structure the ductility to resist. Therefore, we certainly do not use garrison the intensity earthquake action to carry on the structure supporting capacity design, but needs to garrison the intensity earthquake force to reduce a coefficient, is called earthquake force the step-down ratio.

earthquake force the step-down ratio obtains in a big way, the design earthquake function obtains slightly; earthquake force the step-down ratio obtains slightly, the design earthquake function obtains in a big way. Garrisons under the intensity in identical, earthquake force the step-down ratio obtains in a big way, earthquake function smaller, then presses the structure which this small earthquake function designs to submit the standard lowly, meant structure the inelasticity which forms under the corresponding intense degree earthquake distorts in a big way, this request structure has a bigger ductility to guarantee it bigger inelasticity distorts realization, thus proposed to the ductility the request is higher. This ductility rank structure namely for lower design earthquake force value 2 higher ductility requests "high ductility rank" structure. earthquake force the step-down ratio obtains slightly, earthquake function bigger, then presses the structure which this big earthquake function designs to submit the standard high, meant structure the inelasticity which forms under the corresponding intense degree earthquake distorts slightly, this only needs to request the structure to have a smaller ductility to guarantee it smaller inelasticity distorts realization, thus proposed to the ductility the request is lower. This ductility rank structure namely for higher design earthquake force value 2 lower ductility requests "low ductility rank” structure. The same principle, garrisons under the intensity in identical, earthquake force the step-down ratio takes for medium, earthquake function also for medium, thus proposed to the ductility request also for medium. This ductility rank structure namely for medium design earthquake force value 2 medium ductility requests "medium ductility rank” structure. Thus, earthquake force the step-down ratio size has decided the design earthquake force value size in fact, thus has decided to the ductility request size.

The Chinese standard stipulated garrisons the intensity earthquake function to reduce approximately 3 times to carry on the supporting capacity design, namely garrisons the intensity earthquake function response spectrum to eliminate by the earthquake supporting capacity step-down ratio 3, obtains the response spectrum which the design uses. And the Chinese standard according to garrisoned the intensity from in a big way to slightly to propose to the structure ductility from Gao Daodi request, was concrete is indicated with the earthquake resistance rank, altogether divided into levels of, two level of, three level of, four level of four ranks.

The preliminary impression is: China earthquake force the step-down ratio value is somewhat low. This explained as if China earthquake force the value is higher, thus certainly does not need to set the high ductility request to the structure. Actually otherwise, after has contrasted Chinese and the western nation garrisons the earthquake function response spectrum curve, we discovered, in the center long period scope, the west must be higher than China, in other words, China reduces 3 times under the lower response spectrum level, reduces 5times with the west under the higher response spectrum level, even the more after function level is the difference not many, this explained, China to the anti-seismic structure should propose is equal is equal to 5, even high scale to the west earthquake force step-down ratio the high ductility request.

3 several kind of basic earthquake resistances systems performance

• portal frame construction system: According to the above ability design mentality, through the reasonable design, may make the portal frame construction the ductility frame. The ductility frame under the big quake function, after first appears Liang Jiao, appears the column articulation such one kind to consume energy the organization diffusion massive earthquakes energy, the structure can withstand the certain lateral deformation. Therefore the pure portal frame construction is one kind of earthquake resistance performance very good structure. But at the same time us also saw as a result of pure frame anti- side rigidity smaller, creates the side moves the value quite in a big way, therefore the constructive height not suitable too is high. Non- structural unit for instance packing wall under earthquake function, also possibly appears the crack and the destruction. Between the frame and the packing wall rigid joint creates the rigidity increases the effect also possibly to create designs on had not considered increases side force. If is half high packing wall, but also can cause to form the short stump, the rigidity increases, the withstanding very big shearing force, creates the pillar the shearing failure.
• shearing force wall structure system: Shearing force wall structure supporting capacity and rigidity all very big, the side moves distorts slightly, therefore its use scope may be higher than the pure portal frame construction. Is suitable also may use in the shearing force wall to in the portal frame construction component non-linear earthquake resistance performance principle overall, also may design into the shearing force wall the ductility shearing force wall, also may come the diffusion earthquake energy by the stable way. But, in shearing force wall no matter is the wall extremity or Lian Liang, its section characteristic is short and high, this kind of component to detrusion quite sensitive, is easy to appear the crack, is easy to appear the brittle shearing failure. Therefore must carry on the careful reasonable design, only then can enable the shearing force wall to have the good earthquake resistance performance and the good ductility ability. The shearing force wall destruction shape if cuts steps compared to has the very big relations, to cuts steps compared to the very small low wall, the shearing failure shape primarily, the plastic deformation ability is very bad, therefore should avoid in the anti-seismic structure using the low wall. Regarding the bracket wall energy aerodynamic, mainly is leaves the articulation through the wall bottom to carry on. But regarding the joint extremity wall, passes through reasonably supposes the hole position, enable its energy aerodynamic mechanism with to have the strong column weakling’s Liang articulation organization to be similar, forms strong wall weak Liang, namely Lianliang the Liang end leaves the articulation, the wall bottom leaves the articulation, but the wall other places, do not appear the plastic hinge. Otherwise, if LianLiang Qiangyu wall extremity, then can appear with the column articulation organization same level distortion organization. Regarding the longer bracket wall, usually through artificial opens the hole to cause it to turn the joint extremity wall, because the bracket wall took calmly decides the structure, once has a section destruction to expire, can cause the structure to expire and to collapse, but unites the extremity wall to be possible to design ChengQiangqiang weak Liang, leaves the articulation number to be more, consumes energy in a big way. Strongly cuts with the frame design weakly is curved same, Lian Liang Jiqiang the extremity also needs to pass "strongly cuts weakly is curved" enhances its anti- cuts the bearing capacity, postpones the shearing failure, thus improves its ductility. But its own section characteristic influence, the component still cannot guarantee does not have the shearing failure, speciallyLian Liang, in the ordinary circumstances ordinary matches when muscle Lian Liang Hennan realizes the high ductility, the design, must specially take the measure to change its performance.
• frame 2 shearing force walls structure system: Is the frame and the shearing force wall unifies in together resists vertical and the horizontal load one kind of system together, it uses the shearing force wall the high anti- lateral force rigidity and the supporting capacity, makes up the portal frame construction anti- side rigidity to be bad, distorts a bigger weakness. As a result of the shearing force wall and the frame joint operation, improved the pure frame and net shear the wall distortion performance, always distorts reduces, the level distorts reduces, moreover about tends to evenly, about the frame various story posts stress quite is also even. Moreover, under the earthquake function, the shearing force wall undertook the majority of shearing force, the frame has only undertaken very small part of shearing force, usually all was the shearing force wall first submits, after the shearing force wall will submit has the endogenicforce heavy assignment, the frame assignment shearing force can increase, if the earthquake function continued to increase, the portal frame construction also could submit, causes it to form the curve distribution to tally well.

4 conclusions

• compares with the conventional structure static ball plasticity analysis method, considered the earth 2 structures mutually affect the structure static ball plasticity analysis method has its particularity, in the structure static ball plasticity analysis side force distribution pattern, the goal displacement definite method must predetermined.

(2) carries on the consideration earth 2 structures to the comparison rule high level portal frame construction mutually to affect the non-linear earthquake resistance analysis, also may use the non-linear earthquake to respond the time interval analytic method, also may use the static ball plasticity analysis method, two methods both can carryon the earthquake resistance performance appraisal to the structure.

(3) carries on to the high-rise construction structure when the consideration earth 2 structures mutually affects the static ball plasticity analysis, considered Gao Jiezhen the influence, the side distribution pattern best selects the curve distributed pattern.