1 INTRODUCTION Evaluating the performance of deep excavations has always been a difficult task for geotechnical design. The current intensively built environment represents an additional challenge. Hence, the geotechnical de- sign of excavations has to comply not only with the optimization of the structural forces but also with the protection of the adjacent constructions (buildings, utilities network, etc.). Depending on the situation, one needs to assess the influence of the newly con- structed excavation on the neighboring constructions and sometimes, the influences of the newly erected buildings on the already existing excavations. Con- sequently, there is the need for methods which are able to deal in detail with these aspects. The present paper analyzes the most important parameters that control the performance of deep ex- cavations by evaluating the effects on the neighbor- ing buildings and the influence of the existing build- ings upon the response of new excavations. Since the relation between the excavation and its neighbor- ing buildings is considered reciprocal, the effects of new excavations on the behavior of the latter are al- so considered. Moreover, the influence of the build- ing’s type on the excavation–induced deformations is estimated and presented in the framework of vary- ing the parameters for quantifying the performance of excavations with the building-excavation dis- tance. Thus, the relationship between the overburden load exerted by the neighboring building and the performance of the retaining structure of an excava- tion is assessed. The research is motivated by the problems re- garding the performance of deep excavations in soft to medium soils, such as the ones encountered in Bucharest, Romania - for which the geotechnical analysis was conducted. This relies on the need to perform good estimations regarding the soil dis- placements as this is a very important criterion for preventing the damage of neighboring constructions and utility networks. Due to its capacity to integrate constitutive mod- els for simulating real soil behavior, nonlinear finite element analysis represents a rational technique, fre- quently used in current design practice. Thus, nu- merical analysis is a very useful and powerful tool in estimating the excavations response and their recip- rocal relation with the existing neighboring build- ings, thus explaining its use in the current analysis. Assessing the above stated issues requires a ge- otechnical model which is able to provide reliable results. Hence, the characteristics of the model are established based on the statistical analysis of an ex- tended database (Long, 2001 and Capraru, 2012) comprising displacements of retaining walls and ex- cavation-induced displacements from real case stud- ies. This forms the framework in which the analysis in conducted, enabling a method based on which its reliability is demonstrated. Moreover, the results are validated by relating them to the measurements of real case studies comprised in the extended database. Evaluating the influence of deep excavations on neighboring buildings by numerical analysis C. Capraru & D. Adam Institute of Geotechnics, Vienna University of Technology, Vienna, Austria ABSTRACT: The aim of this paper is analyzing the main factors which affect the influence zone of excava- tions (excavation depth, width, distance to neighboring buildings and the load exerted by these, etc.). The im- portance of these factors on estimating the displacements of the retaining structure is briefly described based on finite element analysis results. An extended database on retaining walls and excavation-induced ground displacements is statistically analyzed for conceiving the geotechnical model of the excavation. The latter is further analyzed through varying the above mentioned parameters. The results are validated by comparing them to the data recorded in the extended database and an index for evaluating the excavation influence is proposed. Related to the neighboring building’s number of storeys, this index correlates the maximum lateral deflection of the retaining wall with the maximum settlement behind it.