石砌U型高桥台加固改进对策研究

石砌U型高桥台是西部山区公路建设中广泛采用的结构形式,也是一种受力复杂的砌体结构,在填土荷载和车辆荷载作用下经常发生局部开裂破坏这一有规律性的病害。为研究U型高桥台破坏机理并相应提出改进措施,解决局部开裂破坏问题,以模型试验及三维有限元数值模拟为研究手段,在分析常规U型高桥台破坏机理基础上,研究U型高桥台采用钢筋混凝土圈梁、前侧墙交界处倒角加固改进措施后的变形、破坏规律,分析改进措施的有效性。     

浅析沙沙坡桥梁加固

本文通过沙沙坡桥梁加固实例,简要阐述了重力式U型桥台开裂后运用预应力锚索框格梁等加固的基本方法。     

套拱加固技术在中小跨径拱桥维修中的应用

本文简要阐述了套拱加固维修原理及施工工艺,结合实例介绍运用该加固技术对拱桥U型桥台、主拱圈纵向开裂病害的处理。     

预应力框架技术在加固圬工桥台侧墙上的应用

本文针对浆砌片石桥台侧墙开裂及外鼓的病害特征,提出了一种钢筋混凝土预应力框架加固技术。该技术是通过在桥台两侧侧墙上现浇钢筋混凝土框架来提高侧墙整体性,并达到避免侧墙竖向裂缝的进一步扩展的目的。并通过桥台两侧张拉预应力来达到阻止侧墙继续向两侧外鼓的趋势。实践证明,该方法能有效治理砌石桥台常见病害,可为同类桥台的加固与维修设计及施工实践提供参考。     

桥梁U型钢圈梁及台背注浆法加固处理技术

针对桥台前(侧)墙开裂、桥台背沉陷跳车产生的原因,分析对比了桥梁桥台及台背加固思路及方法,介绍了桥台及台背加固的处理技术,其施工工艺简便,加固处理后压实度和承载力得到了较大提高。     

整体式盖板在U型桥台台后沉陷中的应用研究

通过分析台后沉陷的原因，研究出整体式盖板在解决U型桥台台后填土沉陷问题的技术，实践证明该技术彻底解决了U型桥台因台腔填土沉陷导致侧墙竖向开裂的问题，值得在实际工程中广泛应用和推广。     

某U型桥台开裂原因分析及处治

分析了某U型石砌桥台因排水不良、梁体伸长受限、重车挤压等综合原因,引起台体开裂、挤出变形的病害,并采取了对拉锚索、框架格梁、中空锚杆、钢筋网喷射混凝土等综合加固措施,使桥台病害得以控制。     

郭家湾大桥的加固改造研究

郭家湾大桥建成5a后发现腹拱、桥台、侧墙多处开裂,经过对产生裂缝的原因进行分析后,针对病因提出了注浆、增加桥台基础刚度等加固改造措施。对桥台及挡土墙的施工程序和施工要点作了详细介绍。加固后效果良好,可供其他类似的桥梁加固借鉴。     

石砌U型高桥台破坏机制及对策的模型试验研究

 针对公路建设中出现的高桥台开裂问题进行对比试验研究。设计制作4种尺寸相同的10∶1桥台模型,其中3个桥台模型采用不同构造加强形式,通过对4种桥台模型进行的填土加载和在填土表面施加外荷载,测量桥台前墙和侧墙外表面各点的水平位移进行对比分析,同时对4种高桥台模型进行三维数值计算与对比分析,得出不同构造加强形式高桥台的改进效果非常明显。试验结果表明,在桥台结构中同时采用内倒角和U型钢筋混凝土加劲构件的组合加强构造形式可以将桥台结构抵抗破坏能力提高1倍以上。     

预应力桩静压技术在桥梁加固中的应用

通过对某公路桥梁桥台开裂的病害分析,提出了相应的加固设计方案,并对预应力桩加固施工技术进行了论述,探讨了预应力桩静压技术在桥梁基础加固中的可行性。     

桁架格构式支撑装置在桥面板加固中的应用

与主梁梁肋相比,桥面板一般较薄,由于桥面铺装和防水层的损坏以及渗漏水作用,在水侵蚀、碳化及活载作用下,混凝土桥面板易发生开裂、破损等病害.北京市三环路某T梁桥桥面板严重开裂,病害呈现不断恶化发展趋势,桥面板局部碎裂危及桥梁结构及行车安全.本文依据桥梁试验检测结果,分析病害发生原因,采用格构式钢桁架支撑装置进行桥面板抢修加固,改善了桥面板受力状态,加强了主梁之间横向联系,确保了桥面板大修实施前桥梁结构与桥面行车安全.同时,更为桥面板大修赢得了时间,取得了良好的经济与社会效益.本文所述抢修加固措施可为今后此类桥梁加固设计提供参考.     

某公路U型桥台病害原因分析及加固设计

采用ANSYS软件建立了桥台三维有限元模型,研究了裂缝成因及加固措施,结果表明:桥台在设计荷载作用下的受力状态良好,强度满足要求,通过采取桥台填料换填、注浆以及桥台前墙加固,并改造路面搭板等措施,达到了预期的加固效果。     

高速公路桥(涵)台病害处治中的综合注浆技术

台身开裂、砌体倾斜以及砌体局部凸鼓是石砌桥涵台最为常见的病害,由于石砌石桥涵台自身结构的特殊性以及病害的复杂性,寻求何种有效的加固措施,对于有关单位来说一直是个困扰。本文系统总结了深汕高速公路以注浆为关键工序的对地基持力层钢花管注浆、砌体小孔注浆及台后填土钢花管注浆的综合注浆加固处治技术。检验及分析表明,此处理方法能有效治理石砌桥涵台病害,技术成熟可靠,可为同类桥台的维修加固提供参考。     

高速公路桥涵台背专项处理应用高速液压夯实

针对广梧高速公路K63＋913通道桥1号台台背路基工后沉降现象,结合高速液压夯实机进行补强的作用机理和施工工艺,通过对台背涵侧路基的资料调研,填料土性试验,现场夯实试验等方法进行分析研究,得出了相关结论,并提出建议,以期减少桥涵台背工后沉降。     

桥涵台背回填钻孔注浆处理施工工法

从桥头跳车产生的原因方面进行了论述,介绍了桥梁台背的加固思想和加固机理,并阐述了台背加固的技术要求及施工方法,加固处理后压实度和承载力得到了较大提高,加固效果良好。     

Numerical study of geosynthetic reinforced soil bridge abutment performance under static and seismic loading considering effects of bridge deck

Although the use of Geosynthetic Reinforced Soil (GRS) bridge abutments has been increasing, the seismic performance of such structures has remained a significant concern due to their unknown behavior in load-bearing and stress distribution under bridge load and seismic conditions simultaneously. This paper investigates the static and dynamic response of GRS bridge abutment. A series of numerical models representing the realistic field conditions of these structures, including two reinforced soil walls and a single span deck that restrains the top of walls, rather than equivalent surcharge load, was developed. The calibrated numerical model in FLAC program was used to evaluate the effects of horizontal restraint from the deck on the GRS wall displacements and reinforcement loads at the end of construction and under harmonic base acceleration up to 0.5 g. Results indicated that the restraint mobilized from the bridge deck presence, considerably affected the results at both the end of construction and after the dynamic load was applied. Moreover, a series of the parametric studies were performed to investigate the influences of backfill soil relative compaction, reinforcement stiffness, reinforcement length, and reinforcement vertical spacing on the response of GRS abutments at the end of construction and post dynamic state.     

Experimental study on the load bearing behavior of geosynthetic reinforced soil bridge abutments with different facing conditions

This paper presents an experimental study on reduced-scale model tests of geosynthetic reinforced soil (GRS) bridge abutments with modular block facing, full-height panel facing, and geosynthetic wrapped facing to investigate the influence of facing conditions on the load bearing behavior. The GRS abutment models were constructed using sand backfill and geogrid reinforcement. Test results indicate that footing settlements and facing displacements under the same applied vertical stress generally increase from full-height panel facing abutment, to modular block facing abutment, to geosynthetic wrapped facing abutment. Measured incremental vertical and lateral soil stresses for the two GRS abutments with flexible facing are generally similar, while the GRS abutment with rigid facing has larger stresses. For the GRS abutments with flexible facing, maximum reinforcement tensile strain in each layer typically occurs under the footing for the upper reinforcement layers and near the facing connections for the lower layers. For the full-height panel facing abutment, maximum reinforcement tensile strains generally occur near the facing connections.