MarTREC Data Set for Report: Large Scale Evaluation of Erosion Resistance of Biocementation against Bridge Scour and Roadway Shoulder Erosion

Data set used for the report, "Large Scale Evaluation of Erosion Resistance of Biocementation against Bridge Scour and Roadway Shoulder Erosion". The purpose of the report was to develop an alternative approach for armoring the riverbed with biocementation through MICP to mitigate soil erosion. Long-term erosion exposed to outdoor environment, rainfall induced erosion, and accelerated erosion were conducted on MICP-treated samples to prove the feasibility of the MICP technique for potential applications in prevention of bridge scour and road shoulder erosion. The experimental work and discussion about the testing results indicated that exposing to outdoor environment could result in sharp decrease on UCS for MICP-treated samples. But the MICP-treated samples had better resistance to rainfall induced erosion. The bio-surface treatment gave significant help for cement-treated samples to resist accelerated erosion and water absorption, especially the multiple bio-surface treatments method, no erosion could be measured and 5% lower water absorption was achieved after the cement-treated sample was triple treated by bio-surface treatments. The pure MICP-treated samples were also good at resisting accelerated erosion and water absorption. Furthermore, fiber addition and multiple MICP treatments could improve their resistance. The maximum erosion rate of single MICP-treated samples reduced from 0.16 mm/min to 0 mm/min after triple MICP treatment cycles applied on the samples. Extra MICP treatments on soil samples improved the resistance to water absorption significantly. The triple MICP-treated samples achieved a 6% lower absorption than single-treated samples. All these results indicated that the bio-mediated particulate material based on MICP can provide an effective solution for problematic cases of sandy soil in prevention of bridge scour and road shoulder erosion.本数据集用于题为《生物固化技术抵御桥梁冲刷与路肩侵蚀的大规模评估》的报告。该报告旨在开发一种基于微生物诱导碳酸钙沉淀（Microbially Induced Calcite Precipitation, MICP）的生物固化河床替代加固方案，以缓解土壤侵蚀问题。研究人员针对经MICP处理的试样，分别开展了户外长期暴露侵蚀、降雨诱发侵蚀与加速侵蚀三类试验，以验证MICP技术应用于桥梁冲刷与路肩侵蚀防控的可行性。试验工作与结果讨论表明，户外长期暴露会导致经MICP处理的试样无侧限抗压强度（Unconfined Compressive Strength, UCS）大幅下降；但经MICP处理的试样具备更优异的抗降雨侵蚀性能。生物表面处理可显著提升经固化处理的试样抗加速侵蚀与吸水的性能，其中多次生物表面处理方案效果尤为突出：经三次生物表面处理的固化试样未检测到任何侵蚀现象，且吸水率降低5%。纯MICP处理试样同样具备良好的抗加速侵蚀与吸水性能。此外，纤维添加与多次MICP处理可进一步提升其抗侵蚀性能：单次MICP处理试样的最大侵蚀速率从0.16 mm/min降至经三次MICP处理后的0 mm/min。对土壤试样施加额外的MICP处理可显著提升其抗吸水性能，经三次MICP处理的试样吸水率较单次处理试样低6%。综合所有试验结果可知，基于MICP的生物介导颗粒材料可为砂土类场地的桥梁冲刷与路肩侵蚀防控难题提供高效解决方案。