Study On Anti-seismic And Economic Features Of Steeve-arch Aqueduct (Bridge) Supporting Structure

The destruction of buildings, which caused by earthquakes is not only the main reason leading to the huge people casualties and heavy losses of properties, but also the main object of anti-seismic study. Sometimes the indirect sub-losses are more serious than the direct losses caused by earthquakes in the big industrial zones and metropolitans. The most governments of countries raise definite requirements to the important lifeline engineering. Engineers and scientists of every country are trying to apply and seek all kinds of anti-seismic measurements, and the study on vibrant characters of sorts of arch-bearing structures is one of the hot points. As a brand new supporting structure, the steeve-arch was firstly used in the design of Tangyu Aqueduct (also used as a bridge) lies on the eastern main ditch of Shitou River, Shaanxi Province. The biggest difference from the usual down bearing arch structure lies in this points that the four tectonic cracks on its two down beans can't constrain the level forces. Because of new bearing structure and lack of successful engineering examples domestically and abroad, people have to open out its some characters, such as anti-seismic and tech-economic features. On the contents of two sides abovementined ,this paper attempts to do some initial researches from three angles as follows:1, The analyses of anti-seismic features on longitudinal direction of the aqueductl)The seismic longitudinal effects are small. The vibrant characters are decided from the structure integration and rigidness of piers and main arch-ring of the aqueduct, so the following measures should be taken in order to weaken and isolate seismic influence: properly broadening the section sizes and adopting the high class concrete, lowering the height and barycenter of building, setting hoop steel bars so as to increase the plasticity of the concrete which can absorb the seismic energy and prevent the damages due to stress centralization on the linkages and changing place.2)The structure elements should be laid out symmetrically and uniformly when designing steeve-arch structure, what's more, the reasonable selection of section geometric size near the arch foots of first beams is paid attention to and the arrangement difficultiesof steel bar due to the big eccentric pressures2 , The analyses of anti-seismic features on transverse direction of the aqueductl)The method of adjusting the elements' mass can be harnessed in order to even the layout of seismic loads. For example, no-supporting elements should be made of light material which attracts less seismic loads.2)Generally speaking, seismic combined maximum loads of aqueduct transverse direction is less than 100KN,which present joints near the arch-foot sections. This dynamical features provide conveniences for the selections of section sizes and arranging steel bar. The set of tectonic cracks on down beam is beneficial to anti-seism along the longitudinal and side long of aqueducts.3 , The comparing analyses of tech-economic features, anti-seismic features on transverse direction of the aqueduct1)From the angle of engineering cost, steeve-arch supporting structure, whose down beam have tectonic cracks, can spend less money up to 90% or more than the usual arch supporting structure, namely steeve-arch supporting structure is very obvious on the side of cost.2) From the angle of constructing course, steeve-arch supporting structure requires low-capacity cranes to erect, and simple constructing methods easy to meet. The time spending on construction is short. The usual arch supporting structure requires high-capacity cranes to erect, and complicate constructing methods hard to meet.