Experimental study of head fixity conditions of pile group in sheet-pile bulkhead
(1. State Key Laboratory of Hydrology-water Resources and Hydraulic Engineering，Nanjing Hydraulic Research Institute，Nanjing，Jiangsu 210029，China；2. HydroChina Guiyang Engineering Corporation Limited，Guiyang，Guizhou 550081，China)
(1. State Key Laboratory of Hydrology-water Resources and Hydraulic Engineering，Nanjing Hydraulic Research Institute，Nanjing，Jiangsu 210029，China；2. HydroChina Guiyang Engineering Corporation Limited，Guiyang，Guizhou 550081，China)
Abstract：Laterally loaded vertical piles with load-relief platform has successfully been introduced to deep-water sheet-pile bulkhead so that a part of massive lateral load due to horizontal soil movement can be transferred through pile group on to deeper and larger soil layers to keep the bulkhead stable within allowable displacement limits. Two types of head fixity conditions，capped head and pinned head，are often used in pile group. Obviously，head fixity conditions have great effects on force bearing status and displacement characteristics of cast-in-place piles，load-relief platform and other structural elements in the sheet-pile bulkhead. Two series of centrifuge model tests are carried out to simulate the sheet-pile bulkheads with pile group with two different head fixity conditions. The bending moments of piles and front wall，earth pressures on retaining side of front wall are measured together with tension forces of tie-rod and horizontal displacements of structural elements. It is found that the lateral pile group with capped head is more powerful than the pile group with pinned head in carrying earth pressure load，reducing tension forces of tie-rods and limiting horizontal displacements of structural elements. However，it is also found that the maximum bending moments of piles with capped head occur close to the pile cap level，and the estimated values are equal to the value of pile's maximum allowable bending moment. Therefore，it is appropriate to the lateral pile group with pinned head which can eliminate the above problem while tension force of tie-rod and inclination of front wall due to horizontal displacement can also be controlled within their allowable limits.
徐光明1，李士林2. 板桩码头中群桩基础联接型式的试验研究[J]. 岩石力学与工程学报, 2016, 35(S1): 3365-3371.
(1. State Key Laboratory of Hydrology-water Resources and Hydraulic Engineering，Nanjing Hydraulic Research Institute，Nanjing，Jiangsu 210029，China；2. HydroChina Guiyang Engineering Corporation Limited，. Experimental study of head fixity conditions of pile group in sheet-pile bulkhead. , 2016, 35(S1): 3365-3371.
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2016, Vol. 35 
