Rola badań geofizycznych metodą ERT do oceny szczelności przesłony filtracyjnej głębokich wykopów fundamentowych

This pa per ad dresses the prob lem of as sess ing the leakproofness of the bot tom of a deep foun da tion trench, se cured by cav ity wall, us ing geo phys i cal meth ods of elec tri cal re sis tiv ity to mog ra phy. The study was con ducted on a large con - struc tion pro ject in Lublin, in a place where there are com pli cated soil-wa ter con di tions: the ground wa ter level is above the pro posed depth of foun da tion trench, the sub soil is het er o ge neous, and there are karsted and weath ered car - bon ate sed i ments with con fined aqui fer be low the bot tom of the trench. A hy drau lic frac ture oc curred at the bot tom of the trench dur ing the en gi neer ing works, which caused the wa ter flow into the trench. In or der to rec og nize the soil-wa ter con di tions the first stage of geo phys i cal mea sure ments of elec tri cal re sis tiv ity to mog ra phy (ERT) was made. The ap plied meth od ol ogy al lowed to de ter mine the ex tent of the hy drau lic frac ture zone within the bot tom of foun da tion trench. In or der to as sess the leakproofness of Di a phragm Wall the geo phys i cal ERT mea sure ments were re peated (stage 2) A clear re duc tion in the value of the elec tri cal re sis tiv ity of soils in the area of hy drau lic frac ture was caused by clay in jec tion. The re sults of ERT mea sure ments are dis cussed and graph i cally pre sented.