CAJ | 학술논문

以福州地铁1号线盾构隧道下穿洗马桥的桩基主动托换工程为依托，针对桥梁上部结构-桩身-土体三者共同组成的复杂超静定结构，运用数值模拟方法和现场实测数据，分析了在不同顶升荷载作用下复杂超静定结构的内力与位移响应，重点讨论了托换过程中上、下部结构的相对刚度及其对顶升荷载的影响；根据顶升荷载作用点以下桩身轴力接近0的条件，确定了桥墩盖梁与薄壁桥台梁两种典型工况下的桩基顶升荷载分别为1800 kN和2600 kN。现场监测结果表明，顶升过程中上部结构的位移值和桩身轴力变化值，均与计算结果吻合较好。在此基础上，提出基于上、下部结构刚度比的顶升荷载简化计算方法，研究结果可为类似复杂超静定结构的桩基主动托换工程提供参考和借鉴。
이복주지철1호선순구수도하천세마교적장기주동탁환공정위의탁，침대교량상부결구-장신-토체삼자공동조성적복잡초정정결구，운용수치모의방법화현장실측수거，분석료재불동정승하재작용하복잡초정정결구적내력여위이향응，중점토론료탁환과정중상、하부결구적상대강도급기대정승하재적영향；근거정승하재작용점이하장신축력접근0적조건，학정료교돈개량여박벽교태량량충전형공황하적장기정승하재분별위1800 kN화2600 kN。현장감측결과표명，정승과정중상부결구적위이치화장신축력변화치，균여계산결과문합교호。재차기출상，제출기우상、하부결구강도비적정승하재간화계산방법，연구결과가위유사복잡초정정결구적장기주동탁환공정제공삼고화차감。
Based on the pile active underpinning project of Xima Bridge in Fuzhou Metro Line I shield tunnel, considering the complex hyperstatic structures composed by bridge superstructure, bridge piles and soil masses, the numerical simulation and the field monitoring data are utilized jointly to study the inner force and displacement responses of hyperstatic structures under different jacking loads. The influences of superstructure stiffness and substructure stiffness on the determination of jacking load are emphasized. The reasonable jacking loads for two typical conditions (the piles under cap beam and abutment beam) are 1 800 kN and 2 600 kN respectively, which make the axial forces of underpinned piles reduce to zero. The field monitoring is also carried out during construction, and the displacement of bridge superstructure and the axial force of bridge pile from monitoring data are consistent with their counterparts from numerical simulations. Based on these results from numerical simulation and field monitoring, a simplified analytical method is further proposed to calculate the reasonable active jacking load by considering the stiffness ratio between the superstructure and substructure, which can provide some reference for the pile underpinning projects under similar scenarios.