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（Biocementation）抗桥梁冲刷与路基肩侵蚀的大规模评估》的报告。本报告旨在开发一种通过微生物诱导碳酸钙沉淀（Microbially Induced Calcite Precipitation，MICP）技术采用生物固化工艺加固河床的替代方案，以缓解土壤侵蚀。研究团队对经MICP处理的试样开展了户外长期侵蚀、降雨诱导侵蚀及加速侵蚀试验，以验证MICP技术在预防桥梁冲刷与路基肩侵蚀领域潜在应用的可行性。试验研究与结果分析表明，经MICP处理的试样暴露于户外环境后，其单轴抗压强度（Unconfined Compressive Strength，UCS）会出现显著下降，但经MICP处理的试样对降雨诱导侵蚀具备更优的抵抗性能。生物表面处理可显著提升固化试样抵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后，固化试样未出现可检测的侵蚀现象，且吸水率降低了5%。纯MICP处理试样同样具备优异的加速侵蚀与吸水抵抗性能。此外，添加纤维与多次MICP处理可进一步提升其抗侵蚀与吸水性能。单次MICP处理试样经三次MICP处理循环后，最大侵蚀速率从0.16 mm/min降至0 mm/min。对土壤试样进行额外的MICP处理可显著提升其抗吸水性能。经三次MICP处理的试样，其吸水率较单次处理试样降低了6%。综上所有试验结果表明，基于MICP技术的生物介导颗粒材料，可为砂土类易侵蚀场地的桥梁冲刷与路基肩侵蚀防控提供高效解决方案。