Hydrologic analysis and computation relates directly to the fixing of the span and the general construction scheme of the small and medium highway bridge and culvert——an important part of work in highway engineering.

Study actuality summary of backfilling materials behind abutments of highway bridge and culvert;

Taking the Xuchang-Bozhou Highway and Arongqi-Shenzhen Highway in Henan Province as an example, the present paper analyses the difference of silty sand foundation bearing ability evaluation between "construction foundation standard" and "highway bridge and culvert standard", giving each suitable range,pointing out the main evaluation methods of silty sand foundation bearing ability.

Taking the Xuchang-Bozhou Highway of Henan Province as an example,the difference of silty sand foundation bearing ability evaluation between "construction foundation standard" and "highway bridge and culvert standard" is analysed.

The paper describes the diseases of highway bridge in small and medium rural area, for instance, "single-board force",rust,abutment damage, expansion joint damage, bridge floor rift and riverbed wash.

The location defects and preventive measures for small bridges and culverts;

By using pressure grouting technology for treating back settlement of small bridges and culverts in Beijing-Fuzhou expressway,features,construction organization and the technical measures of pressure grouting technology are introduced,some ideas and proposals are put forward based on this bridge treatment.