我处自1973年在宜珙线试用喷射混凝土护壁法(简称喷护法)代替沉井法开挖圆形桥梁基础取得成功以来,1975年在广罗线施工中,又在地质不良、雨季施工等不利条件下,广泛采用喷护法开挖直径6～12m、深度10m以内的圆形桥基,以及深度较浅的矩形桥基。计先后在 My office since 1973 in the Yichang line test shotcrete retaining wall method (referred to as the spray method) instead of caisson method to excavate the basis of a circular bridge to achieve success since 1975 in the construction of the wide line, but also in poor geological, rainy season construction Adverse circumstances, the widespread use of jetting excavation diameter of 6 ~ 12m, the depth of 10m within the circular abutment, and the shallow depth of the rectangular bridge. Count in succession