Application of electrical resistivity imaging and land surveying in the analysis of underground construction impact on the Warsaw scarp

The pa per pres ents the anal y sis of the II Un der ground Line con struc tion’s im pact on the War saw Scarp with the use of the elec tri cal re sis tiv ity im ag ing (ERI, also known as the elec tri cal re sis tiv ity to mog ra phy) and fur ther to tal sta tion posi tion mea sure ments. The un der ground passes un der the scarp per pen dic u lar in the area of Dynasy Street 6, in Downtown dis trict. The elec tri cal re sis tiv ity im ag ing was per formed for rec og ni tion of the geo log i cal struc ture and a potential land slide sur face or zone. The gra di ent sys tem was used dur ing the prospection. In these anal y ses, the lon gi tu di nal sec tion was 40 m long, and the depth of sur vey amounted to 6 m. In the case of the 200 m long trans verse sec tion, there sulted depth of sur vey was 30 m. The geo phys i cal im age of the lon gi tu di nal sec tion, does not con tain loos en ing soil zones, which could in di cate slip sur face. Next, to tal sta tion mea sure ments, which were tied to the ar chi val geo detic obser va tions’ re sults, were car ried out. The aim of the mea sure ments was to ver ify the ac tiv ity of the hor i zon tal and verti cal dis place ments. The TBM ex ca va tion pro cess led to sum mary ver ti cal dis place ments up to approx. 24 mm and hor i zon tal dis place ments amount ing to approx. 13 mm. To sum up, the cur rent land sur veys re veals mi nor un der ground line’s con struc tion im pact on the scarp dis place ment. Nev er the less, the sen si tive ur ban en vi ron ment re quires fur ther mon i tor ing, es pe cially that the op er a tion loads can re sult in dis place ment rate change.