Study On The Crushing Characteristics Of Calcareous Sand Particles Under Impact Load And Large Load

In some marine areas of China, the calcareous sands are distributed due to someproperties of the organisms, which are different from the characteristics of commonmineral sands.. Therefore, the research on the impact damage of calcareous sand notonly has theoretical value, but also can provide technical reserve and support to themarine engineering construction of calcareous sand distribution area.Are studied in the paper in a sea of biogenic calcareous sand (gravel) underimpact load and static load under the action of particles broken basic rules, throughthe calcareous gravel impact crushing experimental research, found that the protiststexture structure has strong impact resistance capacity for destruction, under the sameimpact, particle crushing particle size is consistent with the same genetic conditions ofcalcareous gravel. The irregular calcareous gravel crushing experiments showed that:the grain size distribution to represent D60has good regularity, initial breakup, thegrain size of D60in7.7~7.9mm, the impact of more times, D60smaller size; theimpact crushing test on the three groups of different gradation of calcareous sand:calcareous sand under the effect of high static load when the particle groups haveparticle damage (crushing or grinding) phenomenon, with the increasing of load,calcareous sand particle breakage degree increases; the coarse particles are moreeasily broken in the large load compaction process, and fine grinding is more likely toeach other; the critical load of fine group the particle breakage is2.73kN; the criticalload of standard particle crushing is2.49kN; the critical load of fine particle breakageis2.24kN; by scanning electron microscopy of sample particle and pore structurewere found in study: fine group particle failure load increases the grinding; coarseparticles in the group occurs when the load increases the fragmentation anddestruction. In the experiment, the fractal dimension of the experimental group wasincreasing, and the particles tended to be fine.. The moduli, geometrical shape, andstress direction of Sui Shi during the impact of the calcareous sand with gravel(Gravel) were studied.Put forward and defined the calcareous sand breakage parameters are given aswell as the new definition of calcareous sand broken form and extent of the damage:according to the br value of calcareous sand particle breakage degree division: Br<2%as micro fracture,2%<Br<4%for primary crushing.4%<Br<6%medium crushing, 6%<Br<8%for strong broken,>8%for severe crushing, formed the degree offragmentation of calcareous sand new discriminant method.The definition of the microscopic fragmentation potential is used to identify thedamage form of the particles.The cause of formation of calcareous sand particles and the zoning map of thefragmentation extent is given. The stability and failure mechanism of the granulargroup under the large static load are studied.