Study of the soil consolidation using reinforced jet grouting by geophysical and geotechnical techniques: “La Normal” building complex (Granada)

Abstract

A great number of damages and injuries affecting buildings are originated either in the foundations or at the supporting ground. This involves a rehabilitation using different techniques of reinforcing and underpinning so as to give the stability back to the architectural collection of buildings. This activity has a great social impact and relevance when dealing with monumental or emblematic constructions where the adopted solution needs to be efficient and safe, and therefore it implies the development of studies before and after the process of rehabilitation to ensure the durability of the intervention. This article shows the research works been done to check the suitability of the adopted solution to consolidate the ground in the restoration of the emblematic building of “La Normal” in Granada. Reinforced jet grouting has been used with the incorporation of fuse elements inserted in the sleeve pipe. It has been defined as a “fuse” since it is a helicoidal tube made of a synthetic material, which can be deformed longitudinally but not transversely and incorporates a spiral steel collar acting as a bellow. With this system, the excessive ground rigidity is avoided as a consequence of the injections which could affect the building if settlements are produced. Seismic techniques have been used, such as the Cross-hole and Down-hole and pressuremetric tests have been carried out to determine the consolidation degree achieved on the supporting soil using reinforced injections. The works carried out serve as a basis to establish actuating and control criteria in soil consolidation treatments using cement–bentonite reinforced jet grouting.