Controlled drilling

Project in brief

Disruption to the surroundings - subsidence, damage to buildings, and nuisance caused by vibrations - must be prevented as much as possible during underground construction, without leading to costly solutions. For this reason, we are developing objective methods and models that can forecast, quantify, and manage the impact on the environment.

In doing so, we not only consider the effects that drilling tunnels have on the environment, but also the effects of, for example, earth-retaining structures when building construction pits. We also investigate the opportunities that soil improvement techniques can offer when managing environmental impact.

Within this project, we are working together with the Centre for Underground Construction as part of the DC-COB Consortium. The research is divided into the eight work packages given below, and closely fits in with field projects such as the North-South line in Amsterdam and the Statenweg Tunnel in Rotterdam. These practical projects take place within the framework of Joint Field Research for Drilled Tunnels (GPB), a research programme that has successfully been carried out within the COB since 2000.

The interest

The standard of living in densely-populated areas can only be maintained if the available space is approached in an efficient way. One option is to use the underground space for functions that cause disruption, and for those that can be carried out without daylight. High-quality knowledge is essential for making use of underground space in a safe, sustainable and affordable way.

Products of knowledge

Forecasting model for damage classification to buildings during tunnel construction Improved forecasts means preventing building damage What is it? Guideline on how to determine the effect of subsidence when constructing tunnels and construction pits on the response of buildings, and how we can divide these buildings in accordance with a damage classification system. What can we use this for? We can determine the response of buildings to ground surface subsidence caused by tunnel/ construction pit building. We can then make a link between the subsidence and eventual damage to nearby buildings and structures. We can predict which buildings close to a construction project are subject to more or less risk of subsidence.   Who will be interested? Principals, engineering consultants, building contractors, supervisory bodies, and insurers. More information jan.rots@tudelft.nl

Assistance for actual collapse safety of drilled tunnels Smarter design of drilled tunnels What is it? Assistance for assessing the constructive safety of a segmented tunnel lining. What can we use this for? On behalf of the Department of Transport, Public Works, and Water Management, the COB is currently working on a new manual for use in the construction and design of tunnels. It includes the results of this research. This involves a model able to determine the margin between the design and actual cases of collapse. Who will be interested? Tunnel builders, principals, designers. More information adrie.vervuurt@tno.nl

Soil improvement techniques: compensation grouting and soil freezing Soil to order: compensation grouting and soil freezing What is it? Numeric model to design soil freezing and a freeze-test set-up to carry out tests. What can we use this for? When building underground structures, the effect on the surroundings can be limited by making local improvements to the soil. For the soil freezing technique, a numeric model is derived from tests carried out in an artificial freezing cell test set-up. We are now able to predict the effects of soil freezing more accurately and to manage them better. Who will be interested? Principals, engineering consultants, building contractors, supervisory bodies, and insurers. More information ger.delange@deltares.nl adam.bezuijen@deltares.nl

COB as a portal for underground use of space and construction New portal makes underground knowledge transparent and accessible What is it? A digital environment that gives access to knowledge that has already been developed for underground construction and the use of space underground. The system starts from the principle of questions, and provides direct access to applications, aspects, and examples. What can we use this for? Via the COB portal, the knowledge developed by Delft Cluster is also distributed by means of manuals and courses, as well as digital project environments in the future. Who will be interested? Anyone working in, or interested in, the world of underground construction and the use of space underground. Principals, contractors, knowledge institutes, and educational bodies. More information wendy.hobma@cob.nl

Geobrain construction vibrations The reliable vibration measure What is it? Forecasting model that incorporates actual field data. Forecasting model based on field experience to estimate and reduce vibrations that may occur when constructing and using underground infrastructure. Field data are now accessible for everyone. Proposals for design guidelines will be distributed via the SBR on the basis of these experiences. What can we use this for? Digital tools are available via www.geobrain.nl so that: • Implementation data for vibrations and vibration-reducing measures during construction activities can be collated. • Improved vibration prognoses can be carried out. • The effectiveness of reduction measures can be assessed. • More critical judgement about the actual probability of damage • Research to assess the quality of vibration measurements The knowledge gained is incorporated into the PAO course ’Vibration hindrance and contact sound insulation in the built environment.’ Who will be interested? Principals, engineering consultants, building contractors, supervisory bodies, and insurers. More information paul.holscher@deltares.nl r.gremmee@pao.tudelft.nl