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滇中引水工程隧洞衬砌施工期温控措施
Temperature Control Measures during Construction Period for the Tunnel Lining of Central Yunnan Water Diversion Project
隧洞衬砌混凝土属于典型的薄壁大体积混凝土,衬砌采用泵送混凝土、水化温升高,围岩约束大,衬砌易产生温度裂缝。为探究合理的隧洞衬砌施工期温控措施,采用三维有限元软件,考虑围岩和衬砌接触,开展了滇中引水工程某隧洞混凝土典型衬砌段施工期的温度场和温度应力场分布规律分析。结合现场监测数据,反馈分析了衬砌段表面保温系数为16.7 kJ/(m2·h·℃)。研究了不同的浇筑温度、浇筑段长度、浇筑季节、混凝土自生体积变形特性对混凝土衬砌温度应力场的影响。结果显示:浇筑温度越高温度应力越大,浇筑温度每升高4 ℃,最小抗裂安全度降低0.30;高温季节浇筑最大应力较大,甚至>3.5 MPa;衬砌结构应采用合适的分段长度;采用微膨胀混凝土有利于抗裂。研究成果可为滇中引水工程隧洞衬砌混凝土温控施工提供参考。
Tunnel lining concrete is a typical example of thin-walled, large-volume concrete. During construction, the high hydration temperature of pumped concrete and the significant constraints imposed by the surrounding rock often lead to temperature-induced cracking. To explore reasonable temperature control measures, we employed three-dimensional finite element software to analyze the temperature field and thermal stress distribution in a typical tunnel lining section of the Central Yunnan Water Diversion Project. Contact elements were used to model the interactions between the surrounding rock and the lining. Based on on-site monitoring data, we performed a feedback analysis on the surface insulation coefficient of the lining section, which was 16.7 kJ/(m2·h·℃). We investigated how different pouring temperatures, section lengths, seasons, and the autogenous volumetric deformation of concrete affect the thermal stress field of the concrete lining. Our findings indicate that higher pouring temperatures increase thermal stress; specifically, a 4°C rise in pouring temperature reduces the minimum anti-cracking safety factor by 0.30. The maximum stress exceeded 3.5 MPa when concrete was poured during high-temperature seasons. Appropriate segment lengths for the lining structure and micro-expansion concrete can enhance crack resistance. The findings offer valuable insights for temperature control in tunnel lining concrete for the Central Yunnan Water Diversion Project.
隧洞衬砌 / 三维有限元 / 温度应力场 / 温控措施 / 抗裂风险 / 滇中引水工程
tunnel lining / 3D finite element analysis / temperature stress field / temperature control measures / cracking risk / Central Yunnan Water Diversion Project
| [1] |
段亚辉, 樊启祥, 苏立, 等. 泄洪洞边墙衬砌混凝土浇筑温控防裂实时控制抗裂安全系数估算[J]. 武汉大学学报(工学版), 2023, 56(4): 387-395.
(
|
| [2] |
牛运华, 潘洪月, 习兰云, 等. 乌东德大坝低热水泥混凝土温控防裂效果研究[J]. 水电能源科学, 2020, 38(5): 98-100.
(
|
| [3] |
涂伟成, 刘松, 张明雷. 船闸大体积混凝土温度及裂缝控制技术[J]. 水运工程, 2015(6): 197-202.
(
|
| [4] |
沈思朝, 颉志强, 王首豪. 基于数值仿真的水闸温控措施敏感性分析[J]. 长江科学院院报, 2022, 39(1): 146-154.
水闸属于薄壁大体积混凝土结构,实践表明,若不采取温控措施,尤其是低温季节施工的混凝土水闸结构在浇筑初期极易出现表面裂缝,后期易扩展为贯穿性裂缝。弄清各温控措施对水闸温度场、应力场及开裂风险的影响,是制定水闸温控指标和防裂措施的前提。以某在建的低温季节浇筑水闸工程为研究对象,利用三维有限元法,计算分析了在低温季节浇筑施工时水闸结构的温度场、应力场特性,重点进行了开裂风险的敏感性分析。结果表明,单一温控措施的防裂效果有限,控温浇筑、表面保温、冷却通水必须相互协调,能有效控制水闸温度应力并避免裂缝产生。
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Sluice is a large-volume concrete structure with thin walls. Practice have shown that concrete sluice structure constructed in low-temperature season is subjected to surface cracks in the early stage of pouring if no temperature control measure is taken, and such surface cracks would penetrate through in later stage. To clarify the influence of temperature control measures on the temperature field, stress field and cracking risk of the sluice is the prerequisite of determining temperature control indices and formulating anti-cracking measures. With a sluice project under construction in low-temperature season as a case study, we examined the spatial and temporal characteristics of temperature field and stress field by simulating the construction process using 3D finite element method. On this basis, we analyzed the sensitivities of stress to pouring temperature, surface temperature preservation, and water cooling. Results manifested that single measure has limited effect. Multiple measures including temperature-control pouring, surface temperature preservation, and water cooling must be coordinated to effectively control the temperature stress of the sluice and avoid cracks.
|
| [5] |
覃茜, 颉志强, 祁勇峰. 船闸闸首混凝土温控防裂研究[J]. 三峡大学学报(自然科学版), 2022, 44(2):43-49.
(
|
| [6] |
张润德, 段亚辉, 方朝阳, 等. 清远枢纽二线船闸混凝土通水冷却智能控制[J]. 中国农村水利水电, 2021(4):188-191,200.
水管通水冷却是大体积混凝土温度控制最常采取的施工温控措施之一，人工操作劳动强度大，成本高。针对船闸结构混凝土温控特点，依据有关规范和借鉴地下水工衬砌混凝土通水冷却智能控制经验，确定了结构混凝土通水冷却智能控制3个参数（通水时间、冷却水温和温降速率），提出了内部温度曲线控制目标和智能控制技术方法，并配套研制了智能化控制设备，在清远二线船闸上闸首底板实践应用。试验结果证明闸首底板混凝土内部最高温度、温降速率全部控制在允许值范围内，全面验证了“温升阶段全时通水降低最高温度、温降阶段间歇性通水控制流量和温降速率”以及终止通水冷却时间控制等技术方法的科学性、适用性，且该智能控制设备操作简便、性能可靠。
(
|
| [7] |
黎汝潮. 三峡工程永久船闸混凝土温控设计[J]. 中国三峡建设, 2001, 8(1):11-13.
(
|
| [8] |
刘利, 高建福, 钱国文, 等. 新疆大石峡水利枢纽无压泄洪洞衬砌混凝土温控防裂研究[J]. 西北水电, 2024(1): 55-61.
(
|
| [9] |
樊启祥, 殷亚辉. 水工隧洞衬砌混凝土温控防裂技术创新与实践[M]. 北京: 中国水利水电出版社, 2015.
(
|
| [10] |
张健, 周顺田, 张圣煌, 等. 泄洪洞衬砌混凝土施工期温控方案比选[J]. 水利规划与设计, 2023(5): 86-91.
(
|
| [11] |
韩刚. 大型隧洞衬砌混凝土施工期及运行期温控分析[D]. 西安: 西安理工大学, 2009.
(
|
| [12] |
李俊, 方朝阳. 围岩特性与衬砌厚度对隧洞衬砌混凝土温度应力的影响[J]. 长江科学院院报, 2016, 33(3): 132-136.
为探明围岩特性与衬砌厚度对衬砌混凝土温度应力的影响,从而制定合理的温控标准,提出了技术可行、经济合理的温控措施,确保了白鹤滩水电站泄洪洞衬砌混凝土具有较高的抗裂安全性。根据白鹤滩水电站泄洪洞衬砌混凝土的结构和材料特性以及边界条件,利用ANSYS对衬砌施工过程中的温度场和应力场进行三维计算。结果表明:衬砌厚度越大,混凝土温度越高,最高温度出现时间越晚;围岩强度越高,衬砌厚度越大,产生的拉应力就越大;而围岩强度越差,衬砌厚度越大,对应的拉应力相对较小。围岩特性与衬砌厚度共同影响着衬砌混凝土温度和温度应力变化趋势,因此,为确保混凝土抗裂安全性,对不同围岩特性的地段应选择不同的衬砌厚度。研究结果可供类似工程参考。
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In order to reduce cracks in the lining concrete of spillway tunnel of Baihetan power station, we discuss the impacts of surrounding rock behavior and lining thickness on thermal stress of lining concrete. On this basis, we make reasonable criteria of temperature control and put forward economical and feasible measures. According to the structure and material properties of lining concrete of the spillway tunnel as well as boundary conditions, we carry out three-dimensional simulation on temperature field and stress field during the construction of lining by using ANSYS. Results show that the larger the thickness of lining concrete is, the higher the concrete temperature is, and the later the maximum temperature comes; moreover, the higher the strength of surrounding rock is, and the larger the thickness of lining concrete is, the higher induced tensile stress is, and the reverse is true. Both surrounding rock behavior and lining thickness have effects on the temperature and thermal stress of lining concrete, so it is necessary to determine lining thickness according to surrounding rock behavior to ensure lining concrete safety on resisting cracks.
|
| [13] |
赵世麒. 隧洞混凝土衬砌施工期温控及防裂技术[D]. 杨凌: 西北农林科技大学, 2006.
(
|
| [14] |
长江科学院. 滇中引水工程隧洞衬砌混凝土全过程防裂关键技术手册[R]. 武汉: 长江科学院, 2023.
(Changjiang River Scientific Research Institute. Key Technical Manual of Cracking Prevention in the Whole Process of Tunnel Lining Concrete of Central Yunnan Water Diversion Project[R]. Wuhan: Changjiang River Scientific Research Institute, 2023. (in Chinese))
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