鑑於微生物由古演化自今有著無窮的潛能、形貌及種類千變萬化，在大自然中無處不有。在岩石、土壤方面，微生物為大自然成岩、礦化之重要因素之一。台灣國土危脆、坡陡流急，大地工程防災之需求日殷，目前地盤改良與邊坡防治等工程需求刻不容緩，本研究嘗試突破傳統地質改良之技術，如物理式地錨工程及化學式地盤灌漿工程等等之習見技術，改用存在於土壤中之微生物改良及固結土壤之技術，進行土木營建結合微生物之研探，藉由仿生工程技術之輔，以取之於自然，用之於自然，達到永續性、長效性之成效，更貼近於大自然之生態工程為本研究之宗旨。
卓雨璇(2011)於台灣本土土壤中，進行系列生理生化實驗研究出兩種具土壤改良之微生物，以此二菌進行砂土圓柱試體改良，藉由超音波脈衝(Ultrasonic Pulse, UP)量測其剪力波速之變化，72小時達到波速提升160%之改良成效。本研究以卓雨璇(2011)之試驗結果與改良方法做比對，以矽之物理性質優於鈣之特性，使用細胞壁成分為二氧化矽之微生物-矽藻(Cylindrical fusiformis)，嘗試從矽藻中找出能使矽酸沉澱之機制，創新研究出可使微生物誘導矽酸進行膠結反應(MISC)之技術，並首次將矽藻結合土木營建對砂性土壤進行改良，同時找出合適的改良方式，對砂土改良前後作化性與物性之成效評估。
經由系列實驗獲致矽藻中具有催化二氧化矽膠結之蛋白，達到沉澱之機制，並與過去大量文獻所使用之巴氏芽孢桿菌(Sporosarcina pasteurii)與矽藻(Cylindrical fusiformis)同時進行微生物式砂土改良之實驗，控制砂土之相對密度(D_r)，並且經由破壞性動態模擬地震之振動試驗、靜態直接剪力與單軸抗壓試驗，再結合非破壞聲學超音波脈衝分析，比較兩微生物改良鈣化與矽化砂土試體之強度成果及剪力波速變化的過程。
破壞性動靜態試驗結果，動態振動試驗模擬921單軸之地震參數，矽化及鈣化改良砂堆試體之坡角於振動前後皆維持不變。靜態抗壓試驗中，矽化砂試體抗壓強度最大為0.9 kgf/cm2；鈣化試體最大為3.4 kgf/cm2，說明微生物改良試體可使砂土擁有自立性。靜態直剪試驗中，於砂土D_r為60%，鈣化改良成果，剪力強度參數之凝聚力(c)提升了0.78 kgf/cm2；矽化改良成果，c提升了0.8 kgf/cm2，驗證了微生物誘導固化機制能使砂性土壤達到改良功效，
非破壞超音波脈衝分析結果，鈣化改良之剪力波速(V_s)提升了4.6倍；矽化改良之 V_s 提升了3.3倍，驗證了微生物使砂性土壤的固化過程，再搭配掃描式電子顯微鏡(Scanning electron microscopy, SEM)及能量色散光譜儀(Energy Dispersive Spectroscopy, EDS )觀測土壤顆粒間微生物之膠結情形。
本研究以矽藻作為結合土木營建之創新技術，未來可結合或取代巴氏芽孢桿菌之仿生技術，提供相關土讓改良工程之參佐，與矽膠結成岩機理之研析。

In view of the infinite potential, morphology and ever-changing variety of microorganisms that have evolved from ancient times to present times, they are omnipresent in nature. In terms of rock and soil, microorganisms are one of the important factors of natural diagenesis and mineralization. In Taiwan, the land is fragile, the slopes are steep and currents are rapid. The demand for land engineering disaster prevention is increasing. The current demand for site improvement and slope prevention and control is urgent. This research attempts to break through the traditional geological improvement technologies such as physical anchor engineering and chemical site grouting engineering, etc. Instead, the improvement of microorganisms in the soil and the consolidation of the soil are utilized so as to carry out the research of combining microorganisms and civil engineering construction. With the aid of bionic engineering technology, the purpose of this research is to take from nature and use it in nature to achieve sustainability and long-term effectiveness, which is closer to nature's ecological engineering.
Jhuo Yu-syuan (2011) conducted a series of physiological and biochemical experiments in the soil of Taiwan and found two kinds of soil improvement microorganisms. The two bacteria were used to improve the sand cylindrical specimen, and the changes in the shear wave velocity were measured by Ultrasonic Pulse (UP), and the improvement effect of the wave velocity increased by 160% in 72 hours. In this study, the test results of Jhuo Yu-syuan (2011) were compared with the improved method. The physical properties of silicon were better than those of calcium. The microbe-cylindrical fusiformis, which has the cell wall component of silicon dioxide, was used. The purpose was to find out the mechanism of silicic acid precipitation from cylindrical fusiformis to innovate the research of the technology that allows microorganisms to induce silicic acid cementation reaction (MISC). It was the first time to combine cylindrical fusiformis with civil engineering to improve sandy soil, and find appropriate improvement methods to evaluate the effectiveness of chemical and physical properties before and after sand improvement.
Through a series of experiments, the protein in cylindrical fusiformis that can catalyze the silica cementation is obtained to achieve the precipitation mechanism. Sporosarcina pasteurii used in a large number of literatures in the past and cylindrical fusiformis were utilized simultaneously to conduct microbial sand improvement experiments. After conducting destructive dynamic vibration, static compression and direct shear tests, and non-destructive ultrasonic pulse analysis, the results were used to compare the strength results and the change process of shear wave velocity.
Destructive dynamic and static test results showed the slope angle of the silicified and calcified modified sand pile specimens was maintained at about 35 degrees when dynamic vibration test simulated 921 uniaxial seismic parameters. In the static compression test, the maximum compressive strength of the silicified sand specimen was 0.54 kgf/cm2; the maximum compressive strength of the calcified specimen was 3.4 kgf/cm2, indicating that the microbial modified specimen can make the sand independent. In the static direct shear test, when the relative density (D_r) of sand is 60%, the result of calcification improvement yielded the cohesion (c) of the shear strength parameter increased by 0.78 kgf/cm2. The result of silicification improvement yielded that c increased by 0.8 kgf/cm2. It is verified that the microbial induced solidification mechanism can achieve the improvement effect of sandy soil,
The results of non-destructive ultrasonic pulse analysis showed that the shear wave velocity (V_s) of the calcification improvement was increased by 4.6 times, and the V_s of the silicification improvement was increased by 3.3 times that verified the cementation process of sandy soil by microorganisms. A scanning electron microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) were used to observe the cementation of microorganisms between soil particles.
This research used cylindrical fusiformis as an innovative technology to combine with civil engineering. In the future, it can be combined with or replace the bionic technology of sporosarcina pasteurii, providing reference for related soil improvement projects, and analysis of the diagenesis mechanism of silica cement.

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