Study And Design On Protection Project Of Du Jiang Yan Limestone Crusher Buildings

Based on the protection requirements of Du Jiang Yan limestone crusher buildings, we studied and designed protection solutions. The study considered falling rock of height 160m and size 0.2m, 1m, and 1.2m respectively. First of all, we proposed four possible protection structures. We then analyzed and discussed in details roof, the most critical part of protection structures and selected the best roof solution. After that we calculated the largest stress under the load of roof gravity, and the load of horizontal earthquake respectively. We also calculated the largest stress under the impulsive force of falling rock. Finally, according to the check calculation of combined stress of protection structures, we made conclusion on reasonable protection structures.The load-bearing and anti-seismic system of the protection structure adopts the combined system of steel beam, concrete-filled rectangular steel tube column, and steel support. The roof consists of structural layer and protective layer on the top. The structural layer adopts two-way steel-concrete composite slab-on-girder structure.The conclusions of roof solution are: (1) For falling rock of size 0.2m, may adopt (soil + two-way steel-concrete composite slab-on-girder structure) solution, with soil layer at least 1m thick; (2) For falling rock of size 1m, may adopt (soil + steel plate + soil + two-way steel-concrete composite slab-on-girder structure) solution, with soil layer at least 2.4m thick, and at least 2m thick above steel plate. The steel plate need to be at least 20mm thick; (3) For falling rock of size 1.2m, may adopt (soil + steel plate + soil + two-way steel-concrete composite slab-on-girder structure) solution, with soil layer at least 3.1m thick, and at least 2.5m thick above steel plate. The steel plate need to be at least 30mm thick.The conclusion of entire protection structure are: (1) For falling rock of size 0.2m, the section size of concrete-filled rectangular steel tube column is 700mm×700mm. The thickness of steel plates of column is 20mm. Columns are filled with C40 concrete. Steel beams are of size 600×500×16×25mm. The thickness of steel-concrete plates is 0.5m. The soil layer covering steel-concrete plates is of 1m thick. (2) For falling rock of size 1m, the section size of concrete-filled rectangular steel tube column is 1100mm×1100mm. The thickness of steel plates of column is 25mm. Columns are filled with C40 concrete. Steel beams are of size 1200×700×25×36mm. The thickness of steel-concrete plates is 0.9m. The protective layer above steel-concrete plate consists of steel plate of thickness 30mm, and soil layer of 1.5m thick above the steel plate, and soil layer of 2.0m thick under the steel plate.