Stability of Geobags in Riverbank Erosion Protection Structures - Experimental and Numerical Study

充砂土工布袋(土工袋)是一种相对较新的防腐系统，但由于其柔韧性和渗透性，它比传统的硬质装甲系统更具优势。土工河护岸结构已经成功地实施了大约15年，主要在亚洲，但在各种水袋和袋-袋界面条件下，元件的稳定性仍然存在不确定性。主要原因是现有的设计公式是针对坚硬材料而制定的，没有考虑到土工标签的弹性性质。阿尔伯塔大学和西北水利咨询公司(NHC)的合作目标是确定影响土工桩稳定性的关键因素，加深我们对土工桩河岸防护系统性能的了解，并开发出可靠的土工桩尺寸设计公式。拟议的研究项目将包括一个大规模的系统实验室，该实验室将与计算模型相结合地进行实验。考虑到土工布的灵活性，将建立施加在袋子表面的水压力和袋子稳定性之间的关系。研究结果将被用来制定尺寸公式，并将被纳入指南。改进后的知识将为土工堤防护岸结构设计标准的制定提供指导和便利。结合过滤性能和稳定性，土工桩是可以从河流系统中移除的临时工程的理想选择，也是后来并入永久性工程的准备工程的理想选择。这项研究将促进土工膜的更广泛应用，这将大大降低与材料、建筑、洪水破坏和随后的修复工作相关的成本，并促进整个加拿大的可持续侵蚀控制。

Sand-filled geotextile bags (geobags) are a comparatively new erosion protection system, howeveradvantageous over traditional hard armour system, credited to their flexible and porous nature. Geobagriverbank protection structures have been implemented with success for about 15 years mostly in Asia, butthere are remaining uncertainties about the element stability under various water-bag and bag-bag interfaceconditions. The main reason is that existing design formulae are made for hard material and do not consider theflexible nature of the geobags. The goals of the partnership between the University of Alberta and theNorthwest Hydraulic Consultants (NHC) are to identify the key factors affecting geobag stability, enhance ourunderstanding of the performance of geobag riverbank protection system, and develop a reliable designformula for sizing the geobags. The proposed research project will include a large-scale systematic laboratoryexperiments in conjunction with computational modeling. The relationships between hydraulic forces exertedon the bag surface and bag stability will be established, taking into consideration the flexibility of the geobags.The findings will be used to develop a sizing formulae and will be incorporated into guidelines. The improvedknowledge will provide guidance and facilitate the development of a design standard for geobag riverbankprotection structures. Combining filter properties with stability, geobags are ideal for temporary works that canbe removed from the river system, as well as preparatory works that is incorporated later into the permanentworks. This research will facilitate wider application of geobags which will greatly reduce the cost related tomaterial, construction, flood damage and subsequent restoration work, as well as promote a sustainable erosioncontrol across Canada.