地震工程学报
地震工程學報
지진공정학보
China Earthquake Engineering Journal
2015年
2期
453-459
,共7页
冻土-桩相互作用%模型试验%地基非线性%动力 BNWF 模型%双向无拉力多段屈服弹簧
凍土-樁相互作用%模型試驗%地基非線性%動力 BNWF 模型%雙嚮無拉力多段屈服彈簧
동토-장상호작용%모형시험%지기비선성%동력 BNWF 모형%쌍향무랍력다단굴복탄황
frozen soil pile interaction%model test%foundation nonlinearity%dynamic beam on nonlinear Winkler foundation (BNWF)model%bidirectional tensionless multi-section yield spring
基于水平循环荷载作用下不同负温冻土环境中单桩动力特性模型试验结果，在已有分析桩-土-结构相互作用的动力 BNWF 模型的基础上，提出改进的冻土-桩基动力相互作用非线性反应分析模型。在该模型中，利用改进的双向无拉力多段屈服弹簧考虑桩侧冻土的水平非线性力学特性，同时兼顾桩侧与冻土间的竖向非线性摩擦效应、桩尖土的挤压与分离作用以及远场土体阻尼对桩基动力特性的影响。其中桩侧水平多段屈服弹簧参数根据冻土非线性 p-y 关系获得，该关系曲线以三次函数曲线段及常值函数段共同模拟，并由室内冻土压缩试验结果确定。最后基于改进的动力 BNWF 模型，提取动位移荷载作用下该桩顶力-位移滞回曲线及桩身不同埋深处的弯矩动响应数值分析结果，并与相应的模型试验结果对比，二者具有较好的拟合度，表明本文所提出的改进模型在分析冻土-桩动力相互作用时有较好的适用性。
基于水平循環荷載作用下不同負溫凍土環境中單樁動力特性模型試驗結果，在已有分析樁-土-結構相互作用的動力 BNWF 模型的基礎上，提齣改進的凍土-樁基動力相互作用非線性反應分析模型。在該模型中，利用改進的雙嚮無拉力多段屈服彈簧攷慮樁側凍土的水平非線性力學特性，同時兼顧樁側與凍土間的豎嚮非線性摩抆效應、樁尖土的擠壓與分離作用以及遠場土體阻尼對樁基動力特性的影響。其中樁側水平多段屈服彈簧參數根據凍土非線性 p-y 關繫穫得，該關繫麯線以三次函數麯線段及常值函數段共同模擬，併由室內凍土壓縮試驗結果確定。最後基于改進的動力 BNWF 模型，提取動位移荷載作用下該樁頂力-位移滯迴麯線及樁身不同埋深處的彎矩動響應數值分析結果，併與相應的模型試驗結果對比，二者具有較好的擬閤度，錶明本文所提齣的改進模型在分析凍土-樁動力相互作用時有較好的適用性。
기우수평순배하재작용하불동부온동토배경중단장동력특성모형시험결과，재이유분석장-토-결구상호작용적동력 BNWF 모형적기출상，제출개진적동토-장기동력상호작용비선성반응분석모형。재해모형중，이용개진적쌍향무랍력다단굴복탄황고필장측동토적수평비선성역학특성，동시겸고장측여동토간적수향비선성마찰효응、장첨토적제압여분리작용이급원장토체조니대장기동력특성적영향。기중장측수평다단굴복탄황삼수근거동토비선성 p-y 관계획득，해관계곡선이삼차함수곡선단급상치함수단공동모의，병유실내동토압축시험결과학정。최후기우개진적동력 BNWF 모형，제취동위이하재작용하해장정력-위이체회곡선급장신불동매심처적만구동향응수치분석결과，병여상응적모형시험결과대비，이자구유교호적의합도，표명본문소제출적개진모형재분석동토-장동력상호작용시유교호적괄용성。
Permafrost is distributed widely in our country.Although pile foundation is the main foundation form for large bridges in frozen zones,few studies have been conducted regarding the dynamic characteristics of pile foundation construction in permafrost.An improved nonlinear ana-lytical model for frozen soil-pile dynamic interaction was developed on the basis of model test results of the dynamic characteristics of pile foundations in various subzero temperature soils under lateral dynamic loads and an analytical model of pile-soil-structure interaction with the dynamic beam on nonlinear Winkler foundation model.This improved analytical model simulates the nonlinear lateral pressure effect of the frozen soil around the pile with an improved bidirec-tional compression-only multi-yield spring.Vertical friction effects between the frozen soil and pile,extrusion and separation effects of frozen soil under pile tips,and damping effects of the far-field soil on the dynamic characteristics of pile foundations are also considered in this analytical model.The parameters of the bidirectional tensionless multi-section yield spring are determined by the nonlinear p-y relationship of frozen soil.The p-y relationship whose parameters were based on the results of the indoor frozen soil compression test was simulated by the combination of a cubic function and a constant function.Displacement-force response of the pile head and pile shaft responses to bending moments at different depths under dynamic forces were very similar to the model test results.Results indicate that the improved analytical model is potentially helpful during the analysis of frozen soil-pile dynamic interactions.
