水平旋喷拱棚结构的承载特性与机理研究  

Study on the bearing characteristics and mechanism of horizontal jet grouting arch structures

作　　者：张慧乐[1,2] 张慧东[1,2] 王述红[3] 柳建国[1,2] 李建可[1,2] 赵琰飞[1,2] 

机构地区：[1]中国京冶工程技术有限公司,北京100088 [2]中冶建筑研究总院有限公司,北京100088 [3]东北大学,辽宁沈阳110819

出　　处：《土木工程学报》2012年第8期131-139,共9页China Civil Engineering Journal

摘　　要：基于现场载荷试验结果与有限元分析方法,深入研究水平旋喷拱棚结构的承载特性与机理。现场试验表明:拱棚结构的荷载-变形曲线可分为三段,即承载力自我调整阶段、稳定承载阶段以及裂缝产生并不断扩展直至破坏阶段;在破坏阶段拱棚结构并未出现突然坍塌,破坏是从旋喷桩体咬合处薄弱面的底部产生裂缝开始,并不断扩展最终贯通引起的。通过分别建立旋喷桩体咬合结构模型与光滑拱结构模型以模拟实际拱棚结构,计算结果表明旋喷桩体咬合结构模型的计算值与实测值吻合较好,光滑拱结构模型的计算结果误差较大。在此基础上,利用有限元方法深入分析了水平旋喷拱棚结构的力学性能,计算结果表明:旋喷桩体的直径与咬合厚度对拱棚结构的承载力影响较大,拱棚结构的形状对承载力的影响相对较小;水平旋喷拱棚结构存在三种破坏模式,裂缝的产生主要受桩体材料抗拉强度的控制。将裂缝的产生与扩展作为水平旋喷拱棚结构破坏前的预警,可为实际工程提供科学依据。Based on the field loading test and finite element analysis of a horizontal jet grouting arch structure, the bearing characteristics and mechanism of the horizontal jet grouting arch structure were studied. The loading test showed that the Q-s curves of the arch structure could be divided into three sections： capacity adjustment stage, stable bearing stage and destruction stage. The sudden collapse of the arch structure did not appear, while the failure was that the cracks occurred in the bottom of the lap weak surface, and the cracks were constantly expanded into transfixion eventually. Through setting up an occlusion structure model of jet grouting piles and a smooth arch model to simulate actual arch structures, the calculation results showed that, the calculated values agreed well with the measured values for the occlusion structure model of jet grouting piles and the calculation results for the smooth arch had large errors. Based on the occlusion structure model of jet grouting piles, the bearing capacity of horizontal jet grouting arch structure was analyzed. The diameter and occlusion thickness of jet grouting piles have more effect on the arch bearing capacity, whereas the influence of arch structure shape is relatively minor. There are three failure modes about horizontal jet grouting arch structure, and the cracks were controlled by the tensile strength of the pile materials. The crack appearance and expansion can be the warning for jet grouting arch before collapse.

关 键 词：水平旋喷拱棚 载荷试验 承载特性与机理 数值模拟 

分 类 号：TU375.4[建筑科学—结构工程]