Implementation documentation for the drainage of the object Aalto Cibulka / Apartment house Aalto Cibulka – design of drainage of the construction pit

Country: Czech republic
Year: 2017 — 2018
Customer: NĚMEC POLÁK, spol. s r.o. & YIT Stavo s.r.o. STEP, spol. s r.o.
Category: Civil engineering, Project management

Main drainage along the pile wall – construction object 01
Pipe length – 510 m
Number of revision shafts – 18 pcs.
Design drainage volume – 0,81 m3/day

Drainage system of front yards – construction object 02
Pipe length – 221 m
Number of revision shafts – 3 pcs
Number of cleansing pieces – 4
Design drainage volume – 1,47 m3/day

Mineral road drainage – construction object 03
Pipe length – 114 m
Number of revision shafts – 1

The construction of a vast-spanning object Aalto Cibulka is planned on the northern bank of the Vidoule hill. It is however located on two different geological layers and the conservative approach of the drainage proposal of the built-up area would change the hydrogeological conditions, leading with a high probability to a serious threat to the upper geological objects which already are at the verge of their stability.
The aim of the implementation documentation was to map the vast hydrogeological area with a subsequent elaboration of a mathematical simulation model and a proposal of an innovative way to stabilize the groundwater level by drainage in three different levels, mutually connected by a series of drainage water overflow in the interaction with elements of specific foundation and the apartment house itself. Building on the results of the simulation hydrogeological model, the implementation documentation of stabilisation of the groundwater level and drainage of the object was performed, including the quantification of investment costs and defining the accompanying potential uncertainties and risks.

Responsible for the mathematical stationary model of hydrogeological conditions in the area of interest, reaching up to the wider hydrogeological conditions of the entire river basin. Responsible for the definition of the scope of subsequent surveying works combining hydrological and topographical input data, and the subsequent elaboration of implementation documentation, designed for two loads taking into account the complicated geological conditions of the Vidoule hill as well as the planned further housing development in the area.

Following the project of groundwater level stabilisation designed for the final stage after the construction of the apartment building Aalto Cibulka, the change of hydrogeological conditions was assessed during the housing object construction. In order to design a plan for the Aalto Cibulka object foundation in demanding hydrogeological conditions a simulation hydrogeological mathematical model was created, including an option for simulating the transient groundwater flow. The individual construction phases of the object that is max. 6,20 m embedded under the terrain level were assessed in relation to their impact on the already built drainage systems. At the same time, the simulation included the impact of the wider area conditions on the stability of the surrounding rock massif, as influenced by the groundwater level affected by the construction. A sensitivity analysis on the proposed drainage objects of the construction pit was performed for the deepest construction phase, with the aim to optimise the technological equipment of the construction and taking account of the interaction with the surrounding hydrogeological conditions.

Responsible for elaboration of the mathematical stationary model of hydrogeological conditions in the area of interest in the transient regime with an overlap into a wider area of hydrogeological riverbed in the course of construction and an optimised proposal of construction pit drainage.