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Thermal performance of cast-in-place piles with artificial ground freezing in permafrost regions
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作者 WANG Xinbin CHEN Kun +3 位作者 YU Qihao GUO Lei YOU Yanhui JIN Mingyang 《Journal of Mountain Science》 SCIE CSCD 2024年第4期1307-1328,共22页
During the construction of cast-in-place piles in warm permafrost,the heat carried by concrete and the cement hydration reaction can cause strong thermal disturbance to the surrounding permafrost.Since the bearing cap... During the construction of cast-in-place piles in warm permafrost,the heat carried by concrete and the cement hydration reaction can cause strong thermal disturbance to the surrounding permafrost.Since the bearing capacity of the pile is quite small before the full freeze-back,the quick refreezing of the native soils surrounding the cast-in-place pile has become the focus of the infrastructure construction in permafrost.To solve this problem,this paper innovatively puts forward the application of the artificial ground freezing(AGF)method at the end of the curing period of cast-in-place piles in permafrost.A field test on the AGF was conducted at the Beiluhe Observation and Research Station of Frozen Soil Engineering and Environment(34°51.2'N,92°56.4'E)in the Qinghai Tibet Plateau(QTP),and then a 3-D numerical model was established to investigate the thermal performance of piles using AGF under different engineering conditions.Additionally,the long-term thermal performance of piles after the completion of AGF under different conditions was estimated.Field experiment results demonstrate that AGF is an effective method to reduce the refreezing time of the soil surrounding the piles constructed in permafrost terrain,with the ability to reduce the pile-soil interface temperatures to below the natural ground temperature within 3 days.Numerical results further prove that AGF still has a good cooling effect even under unfavorable engineering conditions such as high pouring temperature,large pile diameter,and large pile length.Consequently,the application of this method is meaningful to save the subsequent latency time and solve the problem of thermal disturbance in pile construction in permafrost.The research results are highly relevant for the spread of AGF technology and the rapid building of pile foundations in permafrost. 展开更多
关键词 Permafrost engineering cast-in-place pile Artificial ground freezing Thermal performance.
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Field observation of the thermal disturbance and freezeback processes of cast-in-place pile foundations in warm permafrost regions 被引量:1
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作者 Xin Hou Ji Chen +4 位作者 YouQian Liu PengFei Rui JingYi Zhao ShouHong Zhang HaiMing Dang 《Research in Cold and Arid Regions》 CSCD 2023年第1期18-26,共9页
The bearing capacity of pile foundations is affected by the temperature of the frozen soil around pile foundations.The construction process and the hydration heat of cast-in-place(CIP)pile foundations affect the therm... The bearing capacity of pile foundations is affected by the temperature of the frozen soil around pile foundations.The construction process and the hydration heat of cast-in-place(CIP)pile foundations affect the thermal stability of permafrost.In this paper,temperature data from inside multiple CIP piles,borehole observations of ground thermal status adjacent to the foundations and local weather stations were monitored in warm permafrost regions to study the thermal influence process of CIP pile foundations.The following conclusions are drawn from the field observation data.(1)The early temperature change process of different CIP piles is different,and the differences gradually diminish over time.(2)The initial concrete temperature is linearly related with the air temperature,net radiation and wind speed within 1 h before the completion of concrete pouring;the contributions of the air temperature,net radiation,and wind speed to the initial concrete temperature are 51.9%,20.3%and 27.9%,respectively.(3)The outer boundary of the thermal disturbance annulus is approximately 2 m away from the pile center.It took more than 224 days for the soil around the CIP piles to return to the natural permafrost temperature at the study site. 展开更多
关键词 PERMAFROST cast-in-place pile foundations Thermal disturbance Freezeback process Initial concrete temperature
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Refreezing of cast-in-place piles under various engineering conditions 被引量:9
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作者 Lei Guo QiHao Yu +2 位作者 XiaoNing Li XinBin Wang YongYu Yue 《Research in Cold and Arid Regions》 CSCD 2015年第4期376-383,共8页
In the construction of the Qinghai-Tibet Power Transmission Line (QTPTL), cast-in-place piles (CIPPs) are widely applied in areas with unfavorable geological conditions. The thermal regime around piles in permafro... In the construction of the Qinghai-Tibet Power Transmission Line (QTPTL), cast-in-place piles (CIPPs) are widely applied in areas with unfavorable geological conditions. The thermal regime around piles in permafrost regions greatly affects the stability of the towers as well as the operation of the QTPTL. The casting of piles will markedly affect the thermal regime of the surrounding permafrost because of the casting temperature and the hydration heat of cement. Based on the typical geological and engineering conditions along the QTPTL, thermal disturbance ofa CIPP to surrounding permafrost under different casting seasons, pile depths, and casting temperatures were simulated. The results show that the casting season (summer versus winter) can influence the refreezing process of CIPPs, within the first 6 m of pile depth. Sixty days after being cast, CIPPs greater than 6 m in depth can be frozen regardless of which season they were cast, and the foundation could be reffozen after a cold season. Comparing the refreezing characteristics of CIPPs cast in different seasons also showed that, without considering the ground surface conditions, warm seasons are more suitable for casting piles. With the increase of pile depth, the thermal effect of a CIPP on the surrounding soil mainly expands vertically, while the lateral heat disturbance changes little. Deeper, longer CIPPs have better stability. The casting temperature clearly affects the thermal disturbance, and the radius of the melting circle increases with rising casting temperature. The optimal casting temperature is between 2 ℃ and 9 ℃. 展开更多
关键词 cast-in-place pile hydration heat REFREEZING engineering factor PERMAFROST
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Physical modeling of behaviors of cast-in-place concrete piled raft compared to free-standing pile group in sand 被引量:1
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作者 Mehdi Sharafkhah Issa Shooshpasha 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2018年第4期703-716,共14页
Similar to free-standing pile groups, piled raft foundations are conventionally designed in which the piles carry the total load of structure and the raft bearing capacity is not taken into account. Numerous studies i... Similar to free-standing pile groups, piled raft foundations are conventionally designed in which the piles carry the total load of structure and the raft bearing capacity is not taken into account. Numerous studies indicated that this method is too conservative. Only when the pile cap is elevated from the ground level,the raft bearing contribution can be neglected. In a piled raft foundation, pileesoileraft interaction is complicated. Although several numerical studies have been carried out to analyze the behaviors of piled raft foundations, very few experimental studies are reported in the literature. The available laboratory studies mainly focused on steel piles. The present study aims to compare the behaviors of piled raft foundations with free-standing pile groups in sand, using laboratory physical models. Cast-in-place concrete piles and concrete raft are used for the tests. The tests are conducted on single pile, single pile in pile group, unpiled raft, free-standing pile group and piled raft foundation. We examine the effects of the number of piles, the pile installation method and the interaction between different components of foundation. The results indicate that the ultimate bearing capacity of the piled raft foundation is considerably higher than that of the free-standing pile group with the same number of piles. With installation of the single pile in the group, the pile bearing capacity and stiffness increase. Installation of the piles beneath the raft decreases the bearing capacity of the raft. When the raft bearing capacity is not included in the design process, the allowable bearing capacity of the piled raft is underestimated by more than 200%. This deviation intensifies with increasing spacing of the piles. 展开更多
关键词 Free-standing pile group piled raft pileesoileraft interaction Physical modeling cast-in-place concrete piles
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Field study of plastic tube cast-in-place concrete pile
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作者 陈永辉 曹德洪 +2 位作者 王新泉 杜海伟 张霆 《Journal of Central South University》 SCIE EI CAS 2008年第S2期195-202,共8页
The compositions, technical principles and construction equipments of a new piling method used for ground improvement plastic tube cast-in-place concrete pile were introduced. The results from static load tests on sin... The compositions, technical principles and construction equipments of a new piling method used for ground improvement plastic tube cast-in-place concrete pile were introduced. The results from static load tests on single piles with different forms of pile shoes and on their composite foundations were analyzed. The distribution patterns of axial force, shaft friction and toe resistance were studied based on the measurements taken from buried strain gauges. From the point of engineering application, the pile has merits in convenient quality control, high bearing capacity and reliable quality, showing higher reasonability, advancement and suitability than other ground improvement methods. The pile can be adopted properly to take place of ordinary ground improvement method, achieving greater economical and social benefits. 展开更多
关键词 PLASTIC tube cast-in-place concrete pile SOFT ground improvement pile-supported type reinforced EMBANKMENT CONSTRUCTION equipment CONSTRUCTION workmanship
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Influence of the penetration of adjacent X-section cast-in-place concrete(XCC)pile on the existing XCC pile in sand
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作者 Peng ZHOU Jianhui XU +3 位作者 Changjie XU Guangwei CAO Jie CUP Xuanming DING 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2024年第7期557-572,共16页
A series of small-scale 1g X-section cast-in-place concrete(XCC)pile-penetration model tests were conducted to study the effects of soil density and pile geometry on the lateral responses of an existing pile and the v... A series of small-scale 1g X-section cast-in-place concrete(XCC)pile-penetration model tests were conducted to study the effects of soil density and pile geometry on the lateral responses of an existing pile and the variations in surrounding soil stress.The results showed that the bending patterns of existing XCC piles varied with penetration depth.The lateral response of the existing pile was sensitive to the change in relative density and pile geometry.For example,the bending moment of the existing pile increased along with these parameters.The development of the radial stressσ′r/σ′v0 of the soil around an existing pile showed different trends at various depths during the penetration of the adjacent pile.Moreover,the change in radial stress during the penetration of the XCC pile did not exhibit the“h/R effect”that was observed in the free-field soil,due to the shielding effect of the existing piles.The peak value of radial stressσ′r_max/σ′v0 decreased exponentially as the radial distance r/R increased.The attenuation ofσ′r_max/σ′v0 with r/R in the loose sand was faster than in the medium-dense or dense sands.Theσ′r_max/σ′v0 at the same soil location increased with the cross-section geometry parameter. 展开更多
关键词 X-section cast-in-place concrete(XCC)pile Test PENETRATION SAND Lateral response Radial stress
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Study on the Effect of Occlusion Rate on the Deformation of Non-Vegetarian Occlusal Piles
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作者 Yong Deng Hongyang Xie +2 位作者 Yunxue Ye Kaiwei Cao Heng Li 《World Journal of Engineering and Technology》 2022年第3期511-517,共7页
In order to investigate the force characteristics of the occlusal pile, this paper takes the underground garage support project of Nanchang Bayi Square as the research background and studies the bending moment of the ... In order to investigate the force characteristics of the occlusal pile, this paper takes the underground garage support project of Nanchang Bayi Square as the research background and studies the bending moment of the occlusal pile after the excavation process of the foundation pit through the model test. The test results show that the bending moment of the pile increases and then decreases with the increase of soil depth under horizontal load, and the bending moment reaches the maximum near the excavation surface of the foundation pit;the test results can provide a reference for the design of occluded pile body in practical engineering. 展开更多
关键词 occlusion pile Plain pile Model Test Deformation Characteristics
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塑性混凝土咬合桩防渗墙变形机理研究 被引量:2
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作者 梁超 李斌 +2 位作者 刘润 朱楠 李青欣 《河北工程大学学报(自然科学版)》 CAS 2024年第1期23-32,51,共11页
以大连湾沉管隧道南岸港池临时围堰工程监测数据为基础,建立了塑性混凝土咬合桩防渗墙数值计算模型,通过实测数据验证了模型的准确性,分析了不同影响因素下咬合桩防渗墙的变形演化规律,结论表明:水压力相比土压力对咬合桩变形和内力的... 以大连湾沉管隧道南岸港池临时围堰工程监测数据为基础,建立了塑性混凝土咬合桩防渗墙数值计算模型,通过实测数据验证了模型的准确性,分析了不同影响因素下咬合桩防渗墙的变形演化规律,结论表明:水压力相比土压力对咬合桩变形和内力的影响更为显著,水压力增大导致桩身变形和弯矩增大,扰动临时围堰土体;土体坡度的影响较小,但土体坡度应逐渐放缓,不小于1∶1.5;桩长的变化对变形影响较大,较短的桩身未嵌固在岩石中,较长的桩身在桩顶出现最大位移;随着桩径增大,桩顶变形和最大弯矩逐渐增大,弯矩分布较为一致。 展开更多
关键词 咬合桩 防渗墙 水压力 土压力
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基于ABAQUS的咬合桩支护深基坑数值分析
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作者 董和平 董建华 吴晓磊 《兰州理工大学学报》 CAS 北大核心 2024年第4期121-128,共8页
基于ABAQUS数值分析软件,利用刚度等效原则对咬合桩支护深基坑进行等效.对基坑开挖卸荷过程中坑底隆起变形、支护结构位移及支撑轴力变化进行分析,并与实际监测数据进行对比验证.研究结果表明:采用刚度等效原则进行咬合桩支护分析能够... 基于ABAQUS数值分析软件,利用刚度等效原则对咬合桩支护深基坑进行等效.对基坑开挖卸荷过程中坑底隆起变形、支护结构位移及支撑轴力变化进行分析,并与实际监测数据进行对比验证.研究结果表明:采用刚度等效原则进行咬合桩支护分析能够反映基坑的变形特征,数值分析得出的支护结构和周围环境的变形结果与实际监测值具有良好的一致性,可作为基坑实际施工的指导. 展开更多
关键词 基坑开挖 咬合桩支护 数值模拟 坑底隆起变形
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管板组合结构拉森型锁扣咬合数值模拟研究
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作者 皇鹏飞 唐明刚 +2 位作者 胡兴昊 娄学谦 兰金平 《水运工程》 2024年第10期182-187,共6页
针对管板组合结构振打施工过程中的拉森型锁扣容易被撕裂的问题,依托管板组合桩结构形式的尼日利亚莱基深水港码头工程,采用有限元方法对管板组合桩拉森型锁扣拉伸、扭角、倾斜3种咬合情况进行受力仿真研究。结果表明:管板锁扣咬合精度... 针对管板组合结构振打施工过程中的拉森型锁扣容易被撕裂的问题,依托管板组合桩结构形式的尼日利亚莱基深水港码头工程,采用有限元方法对管板组合桩拉森型锁扣拉伸、扭角、倾斜3种咬合情况进行受力仿真研究。结果表明:管板锁扣咬合精度越低,锁扣咬合应力越大,对拉森型锁扣产生越不利的影响,并提出管板锁扣在不同咬合状态下偏移、扭角、垂直度等精度参考限值。最后建议加强对管-板桩沉桩工艺的研究,提高沉桩精度控制与监测,降低锁扣不利的咬合应力,减小锁扣撕裂风险。精度参考限值可为管板组合结构施工技术标准提供依据,以及为提高管板组合结构施工质量提供重要参考。 展开更多
关键词 管板组合结构 数值模拟 拉森型锁扣 咬合应力
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新型桩-墙咬合圆形基坑支护施工技术探析--以S253远松线当阳市河溶大桥危桥改造工程为例
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作者 刘伟明 《江西建材》 2024年第2期230-232,共3页
文中以S253远松线当阳市河溶大桥危桥改造工程为例,对新型桩-墙咬合圆形基坑支护施工技术进行探析,后续基坑变形监测显示,连续墙体的最大侧移为15.1 mm,旋喷桩的最大侧移为10.5 mm,周边的最大沉降量为25.4 mm,满足工程设计的要求。
关键词 桥梁工程 基坑支护 桩-墙咬合 施工技术
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锚碇基坑地下连续墙围护结构作永久受力结构的应用研究
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作者 薛磊 《城市道桥与防洪》 2024年第1期182-185,198,M0015,M0016,共7页
随着地下建设空间的进一步利用,地下连续墙应用范围不断向下拓展。目前,地下连续墙已经作为永久受力结构应用于建、构筑物主体结构中。基于上海远方相关地下连续墙锚碇基坑实践,对地下连续墙作永久受力结构的应用进行探讨,并针对框架式... 随着地下建设空间的进一步利用,地下连续墙应用范围不断向下拓展。目前,地下连续墙已经作为永久受力结构应用于建、构筑物主体结构中。基于上海远方相关地下连续墙锚碇基坑实践,对地下连续墙作永久受力结构的应用进行探讨,并针对框架式地下连续墙、桩-墙咬合式地下连续墙、圆形地下连续墙施工关键技术进行阐述。结果表明,作永久受力了的地下连续墙结构通常较为特殊,部分为特殊结构形式,部分包含特殊接头形式,在目前的施工技术下是可以实现地下连续墙作永久受力结构的。用集约高效,推进城市功能复合。创建“就近职住、功能复合”的现代城市,在规划及设计中进行街道一体化设计。 展开更多
关键词 框架式地下连续墙 桩-墙咬合式地下连续墙 圆形地下连续墙 锚碇基坑
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“干作业钻孔灌注桩+钢套管”咬合桩支护技术 被引量:2
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作者 郑显春 马瑞林 《低温建筑技术》 2023年第2期122-125,共4页
正确选择支护结构是确保深基坑开挖过程中施工安全的关键,文中以海境界二期工程为例,通过对比分析不同深基坑支护方式的施工工艺特点及经济性,结合工程实际条件,确定采用"干作业钻孔灌注桩+钢套管"的咬合桩支护施工方案.重点... 正确选择支护结构是确保深基坑开挖过程中施工安全的关键,文中以海境界二期工程为例,通过对比分析不同深基坑支护方式的施工工艺特点及经济性,结合工程实际条件,确定采用"干作业钻孔灌注桩+钢套管"的咬合桩支护施工方案.重点探讨了咬合桩施工关键技术要点.基坑施工期间,对基坑变形、地面沉降及裂缝等进行全程监测监控,监测数据证明"干作业钻孔灌注桩+钢套管"的咬合桩施工技术在深基坑支护工程中取得了良好效果. 展开更多
关键词 钻孔灌注桩 钢套管 咬合桩 深基坑支护工程
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暗挖车站洞内咬合桩止水施工技术研究 被引量:2
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作者 王振 《施工技术(中英文)》 CAS 2023年第15期127-132,共6页
在政策及水资源保护的大趋势下,地铁建设的地下水控制方案多需采用止水方案。结合北京地铁19号线太平桥站工程,阐述洞内咬合桩止水施工存在的问题,从咬合桩施工工序、施工设备改进、素桩材料选择、垂直度控制、接缝处理、超前探测、侵... 在政策及水资源保护的大趋势下,地铁建设的地下水控制方案多需采用止水方案。结合北京地铁19号线太平桥站工程,阐述洞内咬合桩止水施工存在的问题,从咬合桩施工工序、施工设备改进、素桩材料选择、垂直度控制、接缝处理、超前探测、侵限处理等方面,提出了暗挖车站洞内机械成孔咬合桩止水关键施工技术。研究表明:暗挖车站空间狭小,采用洞内机械成孔施工咬合桩,对钻机和钻杆进行改进,垂直度和咬合效果易保证,进一步提高了施工效率、降低了施工成本;考虑超缓凝混凝土洞内施工的局限性,采用新型膨润土补偿收缩砂浆作为素桩材料,施工时允许素桩凝固,对施工工序要求低,适应性较强,有利于咬合桩的推广应用;应用超前探测技术,提前发现薄弱点及时补强处理,针对不同侵限及渗漏水情况提出处理措施,降低开挖施工风险。 展开更多
关键词 地下工程 咬合桩 机械成孔 垂直度
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复杂地质条件下咬合桩施工质量控制 被引量:2
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作者 李二虎 张宝胜 史艳芳 《建筑技术》 2023年第20期2558-2560,共3页
以粤港澳大湾区深圳都市圈城际铁路深圳机场至大亚湾城际铁路1标车站T4枢纽站基坑为例,针对填土、软土、块石等复杂地层条件,从全套管全回转钻机、咬合桩成孔过程控制、混凝土浇筑过程控制及垂直度控制等方面对咬合桩施工质量进行控制... 以粤港澳大湾区深圳都市圈城际铁路深圳机场至大亚湾城际铁路1标车站T4枢纽站基坑为例,针对填土、软土、块石等复杂地层条件,从全套管全回转钻机、咬合桩成孔过程控制、混凝土浇筑过程控制及垂直度控制等方面对咬合桩施工质量进行控制。基坑开挖后显示桩身完整性、垂直度等良好,从而验证了措施的有效性。总结了成套的咬合桩质量控制方法,为类似工程提供了借鉴。 展开更多
关键词 咬合桩 质量控制 不良地质体
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明挖深埋隧道下穿施工对高速铁路桥梁的影响 被引量:4
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作者 孙武鹏 《铁道建筑》 北大核心 2023年第3期113-117,共5页
甬金高速公路(宁波—金华)改扩建明挖工程下穿杭温高速铁路(杭州—温州)桥梁处挖深超过20 m。本文首先介绍了改扩建明挖工程施工基本原则,然后研究了明挖深埋隧道施工方案,基坑围护、铁路桥墩保护等技术问题,提出对基坑采用钻孔咬合桩+... 甬金高速公路(宁波—金华)改扩建明挖工程下穿杭温高速铁路(杭州—温州)桥梁处挖深超过20 m。本文首先介绍了改扩建明挖工程施工基本原则,然后研究了明挖深埋隧道施工方案,基坑围护、铁路桥墩保护等技术问题,提出对基坑采用钻孔咬合桩+四道内支撑体系围护,对既有高速铁路桥墩基础采用钻孔桩隔离+搅拌桩作为止水帷幕。经数值模拟计算,基坑、高速铁路桥梁桥墩变形均小于规范限值。 展开更多
关键词 高速铁路桥梁 深埋公路隧道 变形控制效果 数值模拟 钻孔咬合桩 止水帷幕
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地铁车站咬合桩围护结构的关键施工控制技术分析 被引量:3
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作者 赵楠 《建筑技术开发》 2023年第1期18-21,共4页
近年来,我国深基坑工程建设中对围护结构的多会使用钻孔咬合桩,尤其是在地铁车站等工程中,咬合桩围护结构的使用率不断提升,且有了极好的应用效果。以绍兴地铁1号线一期工程镜水路站的施工中使用的咬合桩围护结构为例,对建设咬合桩过程... 近年来,我国深基坑工程建设中对围护结构的多会使用钻孔咬合桩,尤其是在地铁车站等工程中,咬合桩围护结构的使用率不断提升,且有了极好的应用效果。以绍兴地铁1号线一期工程镜水路站的施工中使用的咬合桩围护结构为例,对建设咬合桩过程中的位置把握、混凝土凝固时间等主要施工技术进行深入分析,提出技术控制要求和要点,以期为国内同类工程施工提供借鉴。 展开更多
关键词 地铁车站 围护结构 咬合桩 关键技术
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咬合桩施工技术研究 被引量:1
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作者 史恒飞 《科技资讯》 2023年第11期99-102,共4页
咬合桩是一种深基坑的支护结构,具有防渗止水和基坑挡土支护的双重作用,在深基坑的支护工程中被广泛使用。该文通过对咬合桩施工技术的研究,进一步了解和探讨咬合桩的施工方法,以及咬合桩技术在基坑支护方面的应用,积累咬合桩施工的质... 咬合桩是一种深基坑的支护结构,具有防渗止水和基坑挡土支护的双重作用,在深基坑的支护工程中被广泛使用。该文通过对咬合桩施工技术的研究,进一步了解和探讨咬合桩的施工方法,以及咬合桩技术在基坑支护方面的应用,积累咬合桩施工的质量控制方法和施工技术经验,为今后类似工程中的咬合桩施工提供施工方法选择的依据和经验。 展开更多
关键词 咬合桩 施工技术 工艺流程 基坑支护 排桩围护
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Application of a concrete thermal pile in cooling the warming permafrost under climate change 被引量:1
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作者 Yun-Hu SHANG Fu-Jun NIU +2 位作者 Guo-Yu LI Jian-Hong FANG Ze-Yong GAO 《Advances in Climate Change Research》 SCIE CSCD 2024年第1期170-183,共14页
Permafrost degradation caused by climate warming is posing a serious threat to the stability of cast-in-place pile foundations in warm permafrost regions.Ambient cold energy can be effectively utilized by two-phase cl... Permafrost degradation caused by climate warming is posing a serious threat to the stability of cast-in-place pile foundations in warm permafrost regions.Ambient cold energy can be effectively utilized by two-phase closed thermosyphons(TPCTs)to cool the permafrost.Therefore,we installed TPCTs in a cast-in-place pile foundation to create a unique structure called a thermal pile,which effectively utilizes the TPCTs to regulate ground temperature.And we conducted a case study and numerical simulation to exhibit the cooling performance,and optimize the structure of the thermal pile.The purpose of this study is to promote the application of thermal piles in unstable permafrost regions.Based on the findings,the thermal pile operated for approximately 53%of the entire year and effectively reduced the deep ground temperature at a rate of at least-0.1℃per year.Additionally,it successfully raised the permafrost table that is 0.35 m shallower than the natural ground level.These characteristics prove highly beneficial in mitigating the adverse effects of permafrost degradation and enhancing infrastructure safety.Expanding the length of the condenser section and the diameter of the TPCT in a suitable manner can effectively enhance the cooling capability of the thermal pile and ensure the long-term mechanical stability of the pile foundation even under climate warming. 展开更多
关键词 Heat transfer Cold energy Warm permafrost Two-phase closed thermosyphons cast-in-place pile foundation
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Exothermic process of cast-in-place pile foundation and its thermal agitation of the frozen ground under a long dry bridge on the Qinghai-Tibet Railway 被引量:5
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作者 Ya-ping WU Jian GUO +2 位作者 Chun-xiang GUO Wei MA Xiao-jun WANG 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2010年第2期88-96,共9页
A number of dry bridges have been built to substitute for the roadbed on the Qinghai-Tibet Railway,China.The aim of this study was to investigate the exothermic process of cast-in-place (CIP) pile foundation of a dry ... A number of dry bridges have been built to substitute for the roadbed on the Qinghai-Tibet Railway,China.The aim of this study was to investigate the exothermic process of cast-in-place (CIP) pile foundation of a dry bridge and its harm to the stability of nearby frozen ground.We present 3D heat conduction functions of a concrete pile and of frozen ground with related boundaries.Our analysis is based on the theory of heat conduction and the exponent law describing the adiabatic temperature rise caused by hydration heat.Results under continuous and initial conditions were combined to establish a finite element model of a CIP pile-frozen ground system for a dry bridge under actual field conditions in cold regions.Numerical results indicated that the process could effectively simulate the exothermic process of CIP pile foundation.Thermal disturbance to frozen ground under a long dry bridge caused by the casting temperature and hydration heat of CIP piles was substantial and long-lasting.The simulated thermal analysis results agreed with field measurements and some significant rules relating to the problem were deduced and conclusions reached. 展开更多
关键词 Exothermic process of hydration heat cast-in-place (CIP) pile foundation Dry bridge Thermal agitation Frozen ground Qinghai-Tibet Railway
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