Experimental Study on Influence of Blade Width on Bearing Characteristics of Screw Pile in Permafrost Region
Continuous blade screw piles in permafrost regions have no screw blades in the seasonal active layer,and the screw blades in the permafrost layer are interlocked with the permafrost,resulting in good vertical bearing per-formance.To explore the bearing characteristics of continuous blade screw pile in permafrost region,the vertical bearing characteristics of screw pile in permafrost region are explored by means of laboratory test.Finally,the theo-retical calculation formula of vertical bearing capacity in permafrost region is put forward,and the main conclusions are as follows:The bearing capacity of no blades in the load-settlement curves of screw piles with different pitch is much less than that of screw piles with blades,and the pitch has little influence on the bearing capacity of screw piles,and the ultimate load does not increase linearly with the increase of pitch,With the increase of load,the bearing capacity of pile tip increases gradually,and the axial force change of pile without spiral blades is far less than that of pile with spiral blades.The variation amplitude of axial force of screw pile without spiral blades is the same as that of no spiral blades.The variation amplitude of axial force of screw pile with blades is much larger than that without blades,and gradually increases with the increase of blade width.When the pitch is small,the soil between the spiral blades settles with the screw pile blades,while when the pitch is large,the ability of the spiral blades to restrain the soil decreases,and the soil changes gradually from the inner diameter to the periphery.Using the improved formula to calculate the vertical bearing capacity of single pile can effectively estimate the design value of single pile bearing capacity in engineering practice.
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维普
