| 基于HSS模型隧道近接群桩基础施工影响分析 |
| |
| 引用本文： | 王步翔,,周殿文,韩 旭,赵 军,曹亚鹏,王 霜,.基于HSS模型隧道近接群桩基础施工影响分析[J].建筑科学与工程学报,2023,0(2):160-171. |
| |
| 作者姓名： | 王步翔 周殿文 韩 旭 赵 军 曹亚鹏 王 霜 |
| |
| 作者单位： | (1. 中冶华天南京工程技术有限公司,江苏 南京 210019; 2. 河海大学 土木与交通学院,江苏 南京 210024; 3. 中国科学院西北生态环境资源研究院 冻土工程国家重点实验室,甘肃 兰州 730000; 4. 南京铁道职业技术学院 铁道工程系,江苏 南京 210031) |
| |
| 摘 要： | 依托盾构隧道近接侧穿群桩工程建立三维数值分析模型,土体采用小应变硬化(HSS)模型,参数取值借鉴已有研究成果并根据监测位移数据反演,同时考虑土体开挖、衬砌拼装以及盾尾同步注浆等一系列施工工艺措施,并将模拟结果与监测数据进行对比验证,研究了不同工况下地表沉降的形态分布、群桩桩基变形及基桩结构受力,同时考虑地表位移对等代层厚度的敏感性。结果表明:HSS模型能有效预测隧道近接侧穿高架桥桩引起的变形,模拟结果与监测值较吻合; 隧道开挖引起土相对桩产生了滑移,地表沉降及桩身竖向位移在中心线前后各1D(D为管片外径)范围内随推进步数的增加而不断增大,且增加幅度明显减小; 两线推进地表沉降具有叠加效应,最大沉降量增幅达76.8%; 隧道与基桩水平距离越近,引起基桩沉降变化越大,两线推进基桩桩顶沉降增幅达134%; 群桩中各排桩的水平位移变化趋势基本相同,且同排桩的水平位移值相差不大,由于群桩遮挡效应,水平位移值由大到小依次为前排桩、中排桩、后排桩; 桩身水平位移主要在盾构中轴线2.5D范围内,桩身最大水平位移均出现在隧道中轴线附近; 群桩中同排桩桩身附加弯矩及附加轴力沿桩身分布规律相同,桩身最终附加受力与其距离隧道远近有关; 随着注浆充率β的增大,等代层厚度及地表沉降呈线性减小; 穿越段采取的施工工艺方案是有效的,经估算附加弯矩及轴力对桩基承载力的影响在容许范围内。
|
| 关 键 词： | 盾构隧道 群桩基础 HSS模型 位移反分析 变形 受力 |
Influence analysis of tunnel construction adjacent to pile group foundation based on HSS model |
| |
| WANG Buxiang,,ZHOU Dianwen,HAN Xu,ZHAO Jun,CAO Yapeng,WANG Shuang,.Influence analysis of tunnel construction adjacent to pile group foundation based on HSS model[J].Journal of Architecture and Civil Engineering,2023,0(2):160-171. |
| |
| Authors: | WANG Buxiang ZHOU Dianwen HAN Xu ZHAO Jun CAO Yapeng WANG Shuang |
| |
| Affiliation: | (1. MCC Huatian Engineering & Technology Corporation of Nanjing,Nanjing 210019, Jiangsu, China; 2. College of Civil and Transportation Engineering, Hohai University, Nanjing 210024, Jiangsu, China; 3. State Key Laboratory of Frozen Soil Engineering, Northwest Institute of Eco-environment and Resources of Chinese Academy of Sciences, Lanzhou 730000, Gansu, China; 4. Department of Railway Engineering, Nanjing Vocational Institute of Railway Technology, Nanjing 210031, Jiangsu, China) |
| |
| Abstract: | Relying on the pile group project passing through the adjacent side of the shield tunnel, a three-dimensional numerical analysis model was established. The small strain hardening model(HSS model)was adopted for the soil, and the model parameters were retrieved based on the existing research results and the monitoring displacement data. A series of construction process measures such as soil excavation, lining assembly and shield tail synchronous grouting were considered to compare and verify the simulation results with the monitoring data. Under different working conditions, the morphological distribution of surface settlement, the deformation of pile group foundation and the stress of foundation pile structure were studied, at the same time, the thickness sensitivity of equivalent layer of surface displacement was considered. The results show that HSS model can effectively predict the deformation caused by viaduct piles passing through the adjacent side of the tunnel, and the simulation results are in good agreement with the monitoring values.The tunnel excavation causes the soil to slide relative to the pile. The surface settlement and vertical displacement of the pile body increase with the increase of excavation progress within 1D(D is the outer diameter of the segment)before and after the center line, and the increase range is obviously decreasing. The surface settlement promoted by the two lines has a superposition effect, and the maximum settlement increases by 76.8%. The closer horizontal distance between tunnel and foundation pile, the greater change of foundation pile settlement. The increase of pile top settlement of two-line propulsion foundation pile is 134%. The variation trend of horizontal displacement of each row of piles in pile group is basically the same, and the horizontal displacement values of the same row of piles are almost coincident. Due to the shielding effect of pile group, the horizontal displacement value is taken as the front row pile, middle row pile and rear row pile from large to small. The horizontal displacement of pile body is mainly within 2.5D of central axis of shield, and the maximum horizontal displacement of pile body occurs near central axis of tunnel. The distribution law of bending moment and additional axial force along the pile body of the same row of piles in pile group is the same. The final additional force of the pile body is related to its distance from the tunnel. With the grouting filling rate of β increases, the thickness of equivalent layer and surface settlement decrease linearly. The construction technology scheme adopted in crossing section is effective, and the influence of nearby bending moment and additional axial force on the bearing capacity of pile foundation is estimated to be within the allowable range. |
| |
| Keywords: | shield tunnel pile group foundation HSS model displacement back analysis deformation stress |
|
| 点击此处可从《建筑科学与工程学报》浏览原始摘要信息 |
|
点击此处可从《建筑科学与工程学报》下载全文 |
|
