Monitoring Surveys

Monitoring is considered to be one of the most diverse survey disciplines. Murphy Surveys have combined their years of experience and knowledge with identifying market leading partners to enable the provision of a vast range of state of the art monitoring services to all areas of the construction industry.

Monitoring Surveys
Murphy Surveys’ precise equipment measures geo-referenced displacements or movements in one, two or three dimensions. It includes the use of instruments such as total stations, levels, laser scanners, robotics and global navigation satellite system receivers. Our surveyors have extensive experience in tunnel, dam, road, structural and bridge monitoring.

Whether your monitoring requirements are for above ground or below, Murphy Surveys are in a position to offer unrivalled monitoring services specifically designed for:

Monitoring Surveys provided:

• Network and Control Surveys

To meet the high quality demands for underground construction, the creation of highly accurate geodetic networks is essential. Murphy Surveys, with their monitoring partner, GEODATA meets these requirements by using up-to-date methods and instruments. Apart from GPS measurements at the surface, this also includes gyroscopic measurements underground, using the Gyromat 2000. The experience and training of our staff also contributes significantly to the accurate construction of tunnels and cavern constructions of all sizes and complexities.

• Tunnel Laser Scanning

The use of laser scanner systems in tunnel construction projects offers advantages and potentials for use both to owners and construction companies. Virtual spatial recording of the excavation profile enables significant cost savings through targeted quality improvement with respect to the quality of the excavation profile and optimisation of the concrete strength.

By accurately determining the measurements, the scanner recordings can also be utilised as an important basis for billing. Scanner records are also suited for geological purposes (especially when augmented by camera data), for analysis of deformation and to secure evidence

• Heading and Construction Surveys

Surveying is an essential task for economical and quality excavation of underground cavities. Apart from the actual heading control necessary to maintain the required construction tolerances and an optimal excavation profile, numerous setting out tasks also form part of the job. This includes, for instance, setting out of portals and pipe umbrellas and of niches, cross-cuts and inner shells.

The construction of
vertical shafts, inclined shafts and spirals also requires extensive geodetic know-how. For these complex fields of activity, Murphy Surveys and their monitoring partner, GEODATA has the required equipment, experienced staff and proven software solutions.

• Profile Measuring Systems

Producing an excavation profile as accurately as possible is an economic necessity. There are a number of possibilities for monitoring the accuracy of the profile. These include manual measurement of single points or the measurement of many cross-sectional points at arbitrary intervals using profile measuring disks.

Spatial measurements of points in a pre-defined grid are used mainly for registering critical areas and can be used to rapidly control the success of post-profiling work. The use of laser scanners is the most complete and innovative method for documenting a profile.

• Optical 3D Displacement Monitoring

Ever since the manufacturers of electronic total systems introduced instruments onto the market with coaxial distance measurements and accuracies satisfying the demands of the geotechnical engineers, the optical 3D displacement measurement greatly outweighed the thus far conventional convergence measurements, using a precision measuring tape together with levelling.

This provided the geotechnical engineer with a new set of instruments which, for the first time, enabled the
evaluation of absolute displacements in three-dimensional space. Numerous new ways of displaying the results graphically support the geotechnical interpretation of the deformation behaviour of the tunnel surface. Because the measurements are fast, inexpensive and generally do not interfere with the construction activities, it is possible to significantly increase the information density as a function of the geological and geotechnical conditions.

• Optical 3D Deformation Monitoring

Geodetic measuring method for determining three-dimensional displacements of arbitrarily arranged points

• Geotechnical Measurements - Installation, Data acquisition and Analysis

Full range of services related to geotechnical instrumentation

• Geo-Robot Automatic 3D deformation monitoring System

Fully automatic monitoring of building and ground points in real-time with alarm functions

• GPS Deformation Monitoring

Deformation monitoring is the systematic measurement and tracking of the alteration in the shape or dimensions of an object as a result of the application of stress to it. Deformation monitoring is a major component of logging measured values that may be used for further computation, deformation analysis, predictive maintenance and alarming.

Deformation monitoring systems provide a proactive control of a hazard related to possible change or failure of a structure. Policyholders can reduce risk exposure before and during construction and throughout the lifecycle of the structure and hence decrease the insurance premium.

• Vibration Monitoring

Vibration monitoring offers the theoretical assessment of vibration within buildings, with a view to assessing the potential for building damage, disturbance to occupants and likely effects on sensitive machinery.  In addition, we can offer the design and specification of vibration control measures, the measurement and assessment of vibration associated with specific activities and the long term vibration monitoring of quarrying activities, construction etc.

• Noise Measurements

Noise monitoring will determine the most suitable control method to reduce exposure of noise should it be required.  We offer a noise monitoring service for noise in the workplace and environmental noise - this could be for boundary monitoring of industrial sites or noise surveys for planning purposes.

• Settlement or Displacement Monitoring of Structures / Monitoring damage as a result of the presence of pyrite.

The mineral pyrite, also known as “fools gold” is an iron sulphide that expands when exposed to air or water and reacts with oxygen and water to form sulphuric acid.   A common mineral it is not considered a suitable infill in construction.  Pyrite can oxidize in the presence of humidity and form gypsum crystals, which can cause concrete to swell or heave to cause structural defects to the structure such as cracks in the walls or floors or cause an uplift of the structure.   Murphy Surveys can provide the monitoring required to assess the rate at which the presence of pyrite is damaging a structure.

• Monitoring of settlements with a Laser levelling system

Detailed examples of our monitoring works are available upon request

Download this page of our brochure (215kb)
Download our full brochure (1.93MB)