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RailwayPilemonitoringMONITORINGPILE MONITORING SOLUTIONStesting FOR & TESTING THE RAIL SPECIALISTS INDUSTRY Strainstall Pile Testing and Monitoring Specialists www.strainstall.com expertise Bi-Directional Static Load Testing (BDSLT) structural beams. Ground cconditionsondit Time Efficiency Automated Data Acquisition and The Bi-Directional Static Load Test is a well-known static load testing method that uses a time and space and not the test method determine It only takes a few days of Logging saving approach by loading the pile resistance from the mid-pile of near-toe position instead of top loading. the weight of load that can be used. preparation for the installation of the Strainstall’s pileSENTINEL package The BDSLT has gained world wide acceptance for larger diameter (>800mm) cast in-situ concrete piles. pre-manufactured bi-directional is used for automated and The incorporation of strain gauges hydraulic jack(s). continuous monitoring of static Widely adopted in the US, Europe Since the upward skin friction and By using multiple bi-direction jacks within the pile helps to determine loads. The advanced electronic and Asia, engineers and piling end-bearing are measured on a single horizontal plane, the the distribution of load throughout Precision Testing recording system is configured to contractors are increasingly turning separately, there is no guesswork available test capacity can be the shaft length, and the use of Provides engineers with separate provide real-time data recording at data on the end-bearing and friction to the Bi-Directional Static Load as to how much load was carried increased to more than 10,000 embedment strain gauges can defined intervals (that can be as resistance of the shaft Test method due to its by each section. Testing is typically tonnes, and by using multiple jacks provide detailed analysis of soil frequent as every minute), and effectiveness and the breadth of performed until the ultimate on different planes, distinct properties. features easy to use PC-based Cost Efficiency information provided. capacity in either shear or end elements within a shaft can be software that interfaces with In summery, the speed and Has been proven to be more cost baring is reached to determine the isolated for testing. Microsoft Excel. effective than traditional load testing Hydraulically driven, high capacity, accuracy of testing makes the Bi- maximum pile capacity. methods. sacrificial bi-directional jacks are Using this method, scaling errors Directional Static Load Test a pre-installed in the pile with the can be totally eliminated by testing highly useful tool for value Versatility rebar cage, prior to concreting. the full size production piles, and engineering and project redesign. Can be applied to barrette, bored After casting, loading is applied in installing the testing apparatus Benefits and advantages piles (compression or tension), equal and opposite directions - within the pile shaft means the Bi- inclined piles or belled shafts. The upwards against upper skin friction Directional Static Load Test is not Mobility and Space Efficiency test pile can be reused to carry and downward against lower skin restricted by the limits of kentledge Eliminates the need for overhead working loads after testing by friction and end bearing. weight, reaction piles or overhead beams or reaction piles. grouting the pile. Pile Testing and Monitoring Specialists www.strainstall.com innovation Static Load Testing Cross-Hole Sonic Logging Static load testing is used to provide a direct measurement of pile displacement in response to a physically Crosshole sonic logging is a method of verifying the quality and consistency of drilled shafts and other applied test load and is considered to be the bench-mark of pile performance. Suitable for all pile types, concrete piles with the objective of locating defects. Selected bored piles are pre-installed with steel tubes static load testing can be carried out on either production piles or sacrificial test piles. that span the whole axial length before casting. Load testing a pile to failure adequately supported and that and measurements can be A transmitter lowered down into pair of tubes at a particular depth. 3D TomoSonic Software identifies the maximum operating there is sufficient reserve capacity. provided to show lateral, tensile one tube sends a high frequency The entire shaft length is logged TomoSonic is a 3D tomography capacity of a pile and also provides and compressive forces. signal that travels through the and the test is then repeated for imaging tool that supplements the valuable information to design The test pile is subjected to concrete and is detected by a each pair of tubes, allowing for a cross hole analyser output. This engineers. It is recommended for loading using a hydraulic jack, and receiver in the second tube. As full and thorough investigation of analysis is useful in cases where load tests carried out prior to the Strainstall designed and these transmitters are raised and faults both along the length and by cross hole sonic tests reveal a foundation design, as the outcome manufactured high capacity load lowered along the length of the its quadrant. defect, but does not give a precise of the tests are critical in verifying cells are used to measure the load. pile, a cross hole analyser (CHA) indication of its extent. foundation design parameters and Direct measurements of pile records the signals at regular depth The results are mapped and formulating remedial actions if displacement under the applied intervals, and the time that the presented in graphical format to TomoSonic helps visualise the local needed. weight are logged and the test signal takes to travel from the provide qualitative data once defect in two or three dimension results presented in a graphical transmitter to the receiver (first testing is complete. By comparing by producing a 2D or 3D colour Testing on production piles is used format that shows loading versus arrival time), as well as the signal the graphs from the various coded images of the shaft. The to prove that the pile will perform pile head displacement. energy. combinations of access tubes, the TomoSonic software combines satisfactorily at the design load structural soundness of the arrival time data from the scans of plus an overload, to demonstrate Virtually any size of load test can These two parameters will indicate concrete throughout the pile can all pairs of tubes and analyses the that a building or structure will be be performed on land and at sea, the concrete quality between the be established . data and displays it in various views. Pile Testing and Monitoring Specialists www.strainstallmonitwww.strainstall.comoring.com experience High Strain Dynamic Pile Testing Low Strain Dynamic Pile Testing High strain static load testing is a method of testing deep foundations to obtain information about their Low Strain Pile Integrity Testing (also know as the sonic echo or pulse echo method) is a quick and cost capacity and/or to monitor their installation. A Pile Driving Analyser (PDA) is used to record, process and effective way of evaluating the integrity of auger cast-in-place piles, bored shafts, driven concrete piles display data and results. and concrete filled pipes. High strain dynamic pile testing is hammer impact, and process these capacity, pile integrity (including A low strain pile integrity test is travels down the pile at a constant its size and location can be suitable for use on all types of signals after each hammer blow the location and extent of any used to detect potential defects wave speed and produces wave estimated by analysing the drilled and driven piles, and has during driving or restrike to give an damage), the maximum such as major cracks, necking, soil reflections in response to changes propagation and reflection of the the advantage of being conducted immediate graphical visual of the compression/tension forces at the inclusions or voids and, in some in cross sectional area, such as a wave induced on the foundation by in a non-destructive manner. They loading signals for each blow. pile top and toe, and hammer situations, the method can reduction in diameter or a void in the hammer impact. are also less expensive to conduct performance. determine unknown lengths of the concrete. that static load tests, which means Typical results obtained on site piles. The method does not require they can be performed on many include mobilised static load Benefits and advantages advanced planning or access An accelerometer attached to the more piles at a much lower cost Instant preliminary results on site tubes, which makes it the most top or side of the installed pile monitors the impact and resulting and faster speed. Instant checks on the pile integrity affordable option when pile integrity deflections from a small hand-held and the location of any damage is in question. Dynamic measurements of force hammer. The accelerometer signal and velocity are collected by strain Feedback on the maximum tension The name "low strain dynamic test" is evaluated in the field or and compression forces sensors and accelerometers stems from the fact that when a transferred to a PC for further attached to the pile. The PDA Direct measurements of hammer light impact is applied to a pile it analysis by PIT-W, a Windows monitors the strain and input energy and efficiency produces a low strain. The impact based software program. If a acceleration caused by the Cost effective produces a compression wave that defect is present along the shaft, Strainstall has over 45 years experience in the monitoring and testing of structures and components. Our team of qualified geotechnical, mechanical, electronic, civil and structural engineers are well equipped to develop solutions to most instrumentation and monitoring requirements across all engineering sectors. One such sector is the foundation engineering industry, in which we specialise in the provision of high strain dynamic pile testing and analysis, pile integrity testing, consulting services and other specialist testing services.

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