| Mudslide disasters occur more frequently in the Southwest mountainous area of China.With the economic development as well as the establishment of the traffic network in this area,some key road construction projects like constructions of highways,railways,bridges and culverts,are experiencing more and more mudslide disasters.For that,more and more attentions have been paid to studies relating to mudslide disasters in roads and bridges.The outbreaks of mudslide disasters have been recorded frequently in the Reheguge village of Daqing Basin.This situation has caused severe siltation in the S220 ditch bridge and subsequent silted farmland of the downstream coastal areas.Mudslide disasters have become a threat to S220 bridge and culverts as well as lives and property safety of Reheguge villagers.Taking the mudslide disasters in Daqing Basin and S220 bridge as the research object,the present study makes an in-depth analysis to the hazards and formation reasons.The present study conducts a detailed description to startup mode,physical characteristics and development tendency of mudslides in Daqing Basin by analyzing the geographical,terrain and water conditions which contribute to the formation of mudslide in Daqing Basin.The present study calculates the main dynamic parameters of Daqing mudslides,and evaluates the risk of the mudslides and classifies the danger zones.The present study also investigates the destroying modes of Daqing Basin to S220 bridge and culverts.On the basis of the above analysis,the present study uses the analysis of transient dynamics of ANSYS Workbench and studies the reactions of the bridge piers under the pressure of debris flow and hard rocks.Thus,the present has a knowledge of the deformation and stress state of the bridge piers under different construction combinations.The present study also analyzes the destructive laws causes by debris flow impact and dominant factors in a detailed way.Based on the results of the two-way fluid-structure interaction analysis of mudslides and bridge piers,the present study carries out a thorough discussion about the protective measures on bridge piers where frequently occurs mudslide disasters.The present study lists the applicable conditions and characteristics of various protective measures,and analyzes in detail the same cross section area,the counteracting competence of circle piers,rectangular piers and rounded to debris flow impact which are all under the same cross section area.The research results possess instructive significance for the design of bridge piers and bridges in mudslide-stricken areas as well as the choices of protective measures.To effectively guarantee S220 bridge and culverts as well as the wellbeing of the coastal villagers,the present study makes reference to the analogous preventive experience of mudslides and selects "Valley Dam(Gufangba),Rataining Dam(Landangba)plus Beam Dike(Shuliudi)and Bulwark(Fanghudi)" engineering protective measures which feature in blocking and dredging.The present study also conducts stability calculation to the most unfavorable loading combinations of blocking and dredging measures.The calculation results meet the design requirements. |
