| 摘要: | 臺灣地區多數管線皆埋設於道路鋪面下方，且五大維生管線為民生重要管線，管線於地底下的狀況又交錯複雜，為維護既有管線及新設管線，常針對鋪面進行反覆開挖及回填，進而影響道路鋪面服務，也造成道路主管機關維護鋪面及管理上之困難，因此，了解管線挖埋工程對鋪面服務之影響為一重要課題。
考量目前國內尚未有一套CLSM之配比設計規定，另外針對暫修復面層養護後重新刨鋪之時間及厚度亦無確切之規定，常有品質不穩定、過度設計或設計強度不足之疑慮。因此，本研究首先參考ACI-211、ACI-229及施工綱要規範，並考量季節影響情況下依據規範調整為適合國內之CLSM配比設計流程，接著以有限元素法進行管線挖掘鋪面結構分析，分析管線挖掘回填後對路面造成之影響，探討路面結構之力學行為。後續依據研擬之配比流程實際進行管線挖掘之現地試鋪，並針對現地試鋪之面層及CLSM進行相關成效試驗，以驗證本研究調整之配比設計流程及結構分析之合理性。
本研究探討參數包含CLSM參數及管埋深度，利用有限元素分析，了解在不同參數下對暫修復面層之影響，以分析CLSM於暫修復期間強度之發展狀況，及最佳管埋深度等，由結構分析可知CLSM於暫修復養護4天後強度可達穩定狀況；另於現地試鋪中針對CLSM進行暫修復4天後之Clegg衝擊試驗，其結果可達施工綱要規範底層強度CBR大於80%之規定。由前述結構分析及現地試鋪結果可知管線挖掘以CLSM回填應可於暫修復養護4天後進行面層全面刨鋪作業。
另外亦進行不同面層刨鋪厚度之結構分析，分析較常見之刨鋪厚度10公分及20公分可承受之交通量ESALs值，由結構分析可知面層20公分可承受交通量ESALs值大約為10公分之3~4倍；另於現地試鋪中針對面層10公分及面層20公分之斷面進行輕型撓度儀試驗(LWD)試驗，由試驗成果可知AC面層20公分之強度約為10公分之3倍，驗證前述結構分析之合理性。
最後探討現地試鋪之成效試驗結果，由成果可知本研究所建立之CLSM配比設計流程可符合相關規範之要求，亦驗證結構分析之成果，因此本研究最後進行CLSM相關規範探討，希冀藉由本研究成果改善國內CLSM之施工及設計品質。;In Taiwan, most pipelines are buried under the road pavement, and the five vital pipelines are important for people′s livelihood. The underground condition of the pipelines is staggered and complicated. To maintain the existing pipelines and new pipelines, repeated excavation and backfilling are often carried out on the pavement, thus affecting the road pavement service and causing difficulties for the road authorities to maintain and manage the pavement. It is an important subject to understand the influence of pipeline excavation engineering on pavement service.
Considering that there is no set of matching design regulations for CLSM in China at present, in addition, there is no exact regulation on the time and thickness of resurfacing after temporary repair, which is often suspected of unstable quality, excessive design, or insufficient design strength. Therefore, this study first referred to ACI-211, ACI-229, and construction specifications, and adjusted the CLSM ratio design process suitable for domestic by the regulations under the consideration of seasonal influences. Then, the finite element method was used to analyze the pavement structure of pipeline excavation, analyze the influence of pipeline backfilling on the pavement, and discuss the mechanical behavior of pavement structure. Subsequently, in-situ test laying of pipeline excavation was carried out according to the proposed matching process, and relevant effectiveness tests were carried out on the surface layer and CLSM of the testing process, to verify the rationality of the matching design process and structural analysis adjusted in this study.
In this study, parameters including CLSM parameters and tube depth were discussed. Finite element analysis was used to understand the influence of different parameters on the surface layer of temporary repair, to analyze the strength development of CLSM during the temporary repair period, and to the optimal tube depth. The structural analysis showed that the strength of CLSM could reach a stable state after 4 days of temporary repair and maintenance. In addition, the Clegg impact test was carried out on CLSM for 4 days after temporary repair in the site test, and the result can meet the requirement that the bottom strength CBR is greater than 80% in the construction specification. Based on the above structural analysis and the results of in-situ test laying, it can be seen that the pipeline excavation with CLSM backfill can be carried out in a comprehensive surface planning operation after 4 days of temporary repair and maintenance.
In addition, the structural analysis of different planing thicknesses is also carried out. The ESALs values of the common planing thickness of 10 cm and 20 cm are analyzed. From the structural analysis, the ESALs values of the traffic volume of 20 cm are about 3~4 times that of 10 cm. In addition, the light deflection instrument test (LWD) was carried out for the section of 10 cm surface layer and 20 cm surface layer in the ground test pavement. The test results show that the strength of the 20 cm AC surface layer is about 3 times that of 10 cm, which verifies the rationality of the above structural analysis.
Finally, the results of the field test were discussed. It can be seen from the results that the matching design process of CLSM established in this study can meet the requirements of relevant specifications, and the results of the structural analysis were verified. Therefore, the relevant specifications of CLSM were discussed at last in this study, hoping to improve the construction and design quality of CLSM in China by using the results of this study. |
