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コンクリート水路の診断技術および簡易補修工法に関する研究
https://doi.org/10.24514/00002232
https://doi.org/10.24514/00002232c305b23d-32c2-4251-a7a4-433201ff185b
| 名前 / ファイル | ライセンス | アクション |
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nkk_report_No51p37-108p.pdf (23.1 MB)
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| Item type | 紀要論文01 / Departmental Bulletin Original Article(1) | |||||
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| 公開日 | 2019-03-22 | |||||
| タイトル | ||||||
| タイトル | コンクリート水路の診断技術および簡易補修工法に関する研究 | |||||
| タイトル | ||||||
| タイトル | Studies on Technologies for Function Diagnosis and Simple Repair Methods for Concrete Canals | |||||
| 言語 | en | |||||
| 言語 | ||||||
| 言語 | jpn | |||||
| キーワード | ||||||
| 主題Scheme | Other | |||||
| 主題 | ストックマネジメント | |||||
| キーワード | ||||||
| 主題Scheme | Other | |||||
| 主題 | 農業用水路 | |||||
| キーワード | ||||||
| 主題Scheme | Other | |||||
| 主題 | 損傷 | |||||
| キーワード | ||||||
| 主題Scheme | Other | |||||
| 主題 | 破壊試験 | |||||
| キーワード | ||||||
| 主題Scheme | Other | |||||
| 主題 | 劣化予測 | |||||
| キーワード | ||||||
| 主題Scheme | Other | |||||
| 主題 | マルコフ連鎖モデル | |||||
| キーワード | ||||||
| 主題Scheme | Other | |||||
| 主題 | 簡易補修 | |||||
| キーワード | ||||||
| 言語 | en | |||||
| 主題Scheme | Other | |||||
| 主題 | stock management | |||||
| キーワード | ||||||
| 言語 | en | |||||
| 主題Scheme | Other | |||||
| 主題 | irrigation canals | |||||
| キーワード | ||||||
| 言語 | en | |||||
| 主題Scheme | Other | |||||
| 主題 | damages | |||||
| キーワード | ||||||
| 言語 | en | |||||
| 主題Scheme | Other | |||||
| 主題 | breaking test | |||||
| キーワード | ||||||
| 言語 | en | |||||
| 主題Scheme | Other | |||||
| 主題 | Markov chains model | |||||
| キーワード | ||||||
| 言語 | en | |||||
| 主題Scheme | Other | |||||
| 主題 | simple repair methods | |||||
| 資源タイプ | ||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_6501 | |||||
| 資源タイプ | departmental bulletin paper | |||||
| ID登録 | ||||||
| ID登録 | 10.24514/00002232 | |||||
| ID登録タイプ | JaLC | |||||
| 著者 |
森, 丈久
× 森, 丈久 |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | Stock management is a system for appropriately maintaining the functions of the vast number of irrigation and drainage facilities in Japan. Carrying out stock management requires research on and development of technologies to diagnose the functioning of irrigation and drainage facilities, methods to forecast their deterioration, and suitable repair and reinforcement methods. Therefore these studies are aimed at the following: (1) Analysis of defects arising in concrete irrigation canals, (2) development of a technology to investigate the inside of irrigation canal tunnels as water is flowing, (3) formulation of a method to predict deterioration of irrigation and drainage facilities, and (4) development of a simple method to repair small concrete irrigation canals. In Chapter 2, analysis of investigations of damage to irrigation canals from past earthquakes revealed the following: (1) Rising and uneven settlement due to liquefaction were common in irrigation canals on sandy ground; (2) when there were high embankments along a canal's sides, canal sidewalls deformed and collapsed; (3) in cast-in-place concrete canals, concrete cracked and fell off near joints due to the effects of water stops; and (4) with precast concrete blocks and concrete panel canals, blocks and panels collapsed, and canals as a whole were deformed. Breaking tests with specimens simulating a canal joint revealed the following mechanism of damage to canal joints by earthquakes: (1) When joints are compressed lengthwise along a canal, water stops are compressed in a way that pushes them into the canal body; (2) when the water stops are compressed, their ends tend to deform laterally across the canal, leading to tensile strain that exceeds the concrete's critical elongation strain; and (3) as a result, cracks occur near the end of water stops. In Chapter 3, a float-mounted imaging device was developed to discover defects inside irrigation canal tunnels as water is flowing, and which was evaluated for the performance with field tests. It was found that the device is accurate enough to detect cracks of 2 mm or greater width, and that it can also be used to detect toxic gases inside tunnels and otherwise confirm a tunnel's safety before visual inspections by people. At the same time, problems remain to be solved: (1) the device sometimes overlooks defects when its horizontal orientation changes; (2) it is difficult to accurately determine the location and size of an defect; (3) analysis of recorded images is difficult when the water is flowing fast; and (4) underwater images are affected by water transparency. These problems necessitate, for example, future research on attitude control technologies to enable us to obtain stable images, and imaging technologies that are not affected by water flow velocity. Further, an existing underwater robot camera was evaluated for the performance. And it was confirmed that it was able to measure the width of cracks in canal walls in highly transparent flowing water, but that it had difficulty taking images when transparency of the flowing water was poor. It is therefore necessary to research other inspection technologies such as sonic water leakage detectors. In Chapter 4, analysis of the current state of techniques to predict the deterioration of bridges, pavement, and port facilities revealed that many deterioration forecast models use Markov chains. And a deterioration forecast model that applies Markov chains was created by using results of function diagnosis of irrigation and drainage facilities throughout Japan. The deterioration trends of irrigation and drainage facilities were analyzed with this model, and this analysis revealed the following: (1) The ease with which deterioration proceeds in the following concrete structures is indicated in order from greatest to least: Irrigation canals, pipelines, canal tunnels, pumping stations, head works, sluice gates, and dams. (2) Although the tendency for deterioration in mechanical equipment from greatest to least is dams, pumping stations, canals, and head works, differences in deterioration rates between structures are small, and mechanical equipment deteriorates at a faster rate than concrete structures. (3) With respect to electrical equipment, except for dams there is hardly any difference in the probability of transitioning from deterioration state C (sound condition) to deterioration state B (slightly deteriorated condition), and it is therefore about the same as mechanical equipment. Again with respect to electrical equipment, the probability of transitioning from deterioration state B to deterioration state A (seriously deteriorated condition) was far greater for canals and head works than for other structures, which indicates that much equipment is replaced soon after having been found to be deteriorated. (4) Buildings exhibit roughly the same deterioration as concrete structures. Further, comparing the Markov chain model with a quadratic curve type deterioration forecast model found that both models showed the same deterioration trend; that is, the more deterioration proceeds, the faster it proceeds. But the Markov chain deterioration forecast model has some problems such as difficulty in forecasting for certain parts. This will necessitate accumulating year-on-year function diagnosis data categorized by facility and material, and creating deterioration forecast methods tailored to individual deterioration mechanisms. In Chapter 5, analysis of the defects seen in small concrete irrigation canals and the existing repair methods revealed that most defects are damaged joints, and that the materials mainly used to repair joints are cement mortar and resin. It was also revealed that places repaired using cement mortar materials often deteriorate again, as when the repair material cracks or falls off. This is probably due to the inability of repair materials to keep up with the expansion and contraction behavior of the joints in response to temperature changes. And it was also revealed that cracks and other deterioration occurred again in places repaired using resin sealants. This is probably due to UV-caused deterioration. Further, existing joint repair methods require widening joints with a disk grinder, showing that procedures must be made simpler. Next a simple joint repair method using a sealant combined with a covering tape was developed, and which was evaluated for the performance with laboratory and field tests. These tests revealed the following: (1) Leak tests found no leaking in laboratory or on-site irrigation canals, showing that the method has good sealing performance. (2) Comparing the adhesive strength of sealant alone found that polyurethane resin sealant is better than silicone resin sealant. (3) Covering the polyurethane resin sealant with the covering tape improves the adhesive strength of the sealant. (4) Polyurethane resin sealant combined with the covering tape has the ability to expand 6.92 mm. (5) The developed repair method is simple enough to allow farmers with no such repair experience to perform the operation in a short time. (6) Field tests found that the developed repair method has enough durability so that defects will not appear for two years after repair. Future research will determine the adhesive strength required of the sealant in combination with the covering tape, and will use a follow-up study on repairs made in the field to verify whether the developed repair method has the intended number of durable years (three to five years). | |||||
| 書誌情報 |
農村工学研究所報告 en : Bulletin of the NARO, Rural Engineering 巻 51, p. 37-108, 発行日 2012-04-26 |
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| 出版者 | ||||||
| 出版者 | 独立行政法人 農業・食品産業技術総合研究機構 農村工学研究所 | |||||
| ISSN | ||||||
| 収録物識別子タイプ | ISSN | |||||
| 収録物識別子 | 1882-3262 | |||||
| DOI | ||||||
| 関連タイプ | isIdenticalTo | |||||
| 識別子タイプ | DOI | |||||
| 関連識別子 | 10.24514/00002232 | |||||
| 著者版フラグ | ||||||
| 出版タイプ | VoR | |||||
| 出版タイプResource | http://purl.org/coar/version/c_970fb48d4fbd8a85 | |||||
