Method of supporting foundation pit in soft layer with brad

The present invention is method of supporting foundation pit in soft layer with brad. Around the foundation pit, antiseepage veil comprising cement and soil stirring pile, high pressure rotarily sprayed pile or densified grout is formed to separate water and stabilize the soil wall. Then, brads are inserted via the veil into soil around the foundation pit, and the brads are hollow ones, into which cement mortar is grouted. The soil slope is reinforced through inclined grouting. Finally, the exposed parts of the brads are connected with steel bar and steel wire net, and concrete surface layer is sprayed. The method of the present invention may be in soft soil layer with relatively high underground water level. 一种利用土钉支护软弱地层基坑的方法，所述的方法是在基坑的周围设置有防渗帷幕，所述的防渗帷幕由水泥土搅拌桩、高压旋喷桩或压密注浆构成，这样解决了土体的隔水性、自立性以及土体开挖过程中土壁的稳定性。其次，在基坑的四周插入土钉，所述的土钉穿过防渗帷幕，进入土体，所述的土钉为中空的管材，在所述的土钉中注入水泥浆或水泥砂浆，然后以水平向下倾斜的压密注浆或二次压力灌浆加固坡后土体，最后，将所述的土钉外露端使用钢筋和钢筋网连接起来，最后喷射混凝土面层，形成配筋的喷射混凝土面层，本发明可用于地下水位较高，由饱和的粉质粘土、淤泥质粘土等组成的软弱地层中。