Transmission And Consumption Law Of Low Level Single-point Impact Energy In Red Sandstone Soil

Red Sandstone is widely distributed in southern Jiangxi,and it is the main foundation backfill material of the area.During the foundation engineering,it often choose dynamic compaction which reinforcing effect remarkable,effective reinforcement depth,construction equipment simple to construct.But research about tamping passes and consumption of energy in red sandstone soil is relatively small.The paper chooses Gannan red sandstone soil as the research objection to analysis the impact of single-point load energy transfer and consumption law with the impact load test by static pile indoor and secret trials,we reached the following conclusions:(1)When the soil density,the range of level energy transfer of light hammer falling from the high is greater than the weight from the low.Bottom surface is bounded to the ram,and the transfer goes to a large range of small funnel.When the upper and lower density of the soil is uniform and the lower portion dense,more conducive to the energy to the deep pass.(2)During impact action,light hammer falling from high is more favorable to the energy transfer within the soil along the vertical ram pit than the weight from the low,while tamping outside the pit is opposite..When the soil density is uneven,easier transfer of energy to the depths in the dense upper case.(3)Soil particle size of impact to energy consumption effect is very significant,the change of grain size range from 5 to 20 mm of vertical energy consumption accounted for a percentage of the total energy(energy consumption rate)is up to 54.66%,horizontal to the maximum was 58.3%;while particle size of 0 to 5mm vertical energy consumption rate maximum is only 30.79%,the level to a maximum of only 44.86% and the loss nearly 46% of total energy(4)Different thickness of soil,the vertical energy consumption are much larger than the horizontal direction,but as the thickness and the total impact energy increases,the gap between them decreases.The horizontal direction,the energy consumption rate gap between different thickness of soil are significant,and the original soil samples proportional to the thickness,up to 31.65%.Vertical impact energy mainly consumed in the soil near the bottom of the pit ram and near half of the total energy.The conclusions will be helpful to further study of the transmission and consumption lawof which impact point is not located near the lower ram,and it also has a certain reference function to design to dynamic compaction reinforcement in the corner of the ground area.