岩土力学
巖土力學
암토역학
ROCK AND SOIL MECHANICS
2013年
4期
1131-1139
,共9页
倒T型导管墙桩基防坡堤%有限元%土压力%p-y曲线%稳定性%简化方法
倒T型導管牆樁基防坡隄%有限元%土壓力%p-y麯線%穩定性%簡化方法
도T형도관장장기방파제%유한원%토압력%p-y곡선%은정성%간화방법
inverse T type breakwater with jackets and pile foundations%finite elements%earth pressure%p-y curves%stability%simplified calculation methods
倒T型导管墙桩基防波堤作为新型港工结构,主要依靠桩基和自身重力维持稳定.以天津港水文地质条件为算例,建立三维弹塑性有限元模型,通过荷载-位移关系曲线,确定稳定性安全系数.分析极限状态下桩基沿环向与竖向的土压力分布,得出桩侧极限水平土抗力,并将有限元结果与美国规范API土抗力计算方法进行比较.造成防波堤结构失稳的原因主要有两个,即结构自身无法满足强度要求和土体达到极限.结构自身强度达到极限时,可用p-y曲线有限差分迭代法求取安全系数;土体达到破坏极限时,可分别假定转动点位于桩轴线上和偏离桩轴线两种情况,利用极限平衡法,建立抗倾稳定性简化计算方法.经验证,理论方法得到的稳定性安全系数与有限元结果比较接近.
倒T型導管牆樁基防波隄作為新型港工結構,主要依靠樁基和自身重力維持穩定.以天津港水文地質條件為算例,建立三維彈塑性有限元模型,通過荷載-位移關繫麯線,確定穩定性安全繫數.分析極限狀態下樁基沿環嚮與豎嚮的土壓力分佈,得齣樁側極限水平土抗力,併將有限元結果與美國規範API土抗力計算方法進行比較.造成防波隄結構失穩的原因主要有兩箇,即結構自身無法滿足彊度要求和土體達到極限.結構自身彊度達到極限時,可用p-y麯線有限差分迭代法求取安全繫數;土體達到破壞極限時,可分彆假定轉動點位于樁軸線上和偏離樁軸線兩種情況,利用極限平衡法,建立抗傾穩定性簡化計算方法.經驗證,理論方法得到的穩定性安全繫數與有限元結果比較接近.
도T형도관장장기방파제작위신형항공결구,주요의고장기화자신중력유지은정.이천진항수문지질조건위산례,건립삼유탄소성유한원모형,통과하재-위이관계곡선,학정은정성안전계수.분석겁한상태하장기연배향여수향적토압력분포,득출장측겁한수평토항력,병장유한원결과여미국규범API토항력계산방법진행비교.조성방파제결구실은적원인주요유량개,즉결구자신무법만족강도요구화토체체도겁한.결구자신강도체도겁한시,가용p-y곡선유한차분질대법구취안전계수;토체체도파배겁한시,가분별가정전동점위우장축선상화편리장축선량충정황,이용겁한평형법,건립항경은정성간화계산방법.경험증,이론방법득도적은정성안전계수여유한원결과비교접근.
The inverse T type breakwater with jackets and pile foundations is a new type of structure applied to port and coastal engineering, of which the stability is sustained by pile foundations and gravity. In terms of the hydrogeological conditions of Tianjin Port, a 3D elastoplastic finite element model is estabilished for stability analysis of the inverse T type breakwater with jackets and pile foundations. The safety factor of stability is determined by P-S curve. The soil resistance is calculated by analyzing the vertical and circumferential distributions of earth pressure on pile foundations in the limit state. Besides, the earth resistance calculated by the finite element method is compared with API. There are two main reasons which cause structural instability:Firstly, the structure itself is unable to meet strength requirement;Secondly, the soil is in the limit of state. For the first reason, calculate the safety factor of stability by p-y curve method. When the soil is in the limit state, simplified methods for anti-overturning stability based on the rotation point which is on the pile axis or deviates from the pile are set up. In comparison to finite element method, simplified calculation method is reliable.