NFP - Center of Foundations and Prospecting

NFP works are including of: Testing and analysis of piles, site  investigation, geotechnical monitoring. We have the ability of  analyzing complicated geotechnical engineering also, such as  the design and general analyzing calculation for soft foundation,  reclamation, stability of sea dyke and slope, pile foundation and  deep excavation, etc. All of our works are according to international  standard (ASTM, BS, etc.) and “Regulamento de Fundações”. 

1. Testing and analysis of pile foundations

Perform tests and provide analysis of deep and shallow foundation,  which are generally used for large and medium projects (LRT,  Public House, Bridge and Terminal) in Macau. Field tests are  including in pile static loading test, pile dynamic loading test, pile  sonic integrity test, pile driving analysis, koden test, cross-hole  sonic logging test, anchor pull out test and pneumatic drilling test.  NFP has many experienced engineers and technicians for pile tests  with advanced test equipments. 

(Pile Test Team)

1.1 (Pile Sonic Integrity Test, SIT)

Sonic Integrity test is a kind of non-destructive test. This test  is used to test the integrity and continuity of a pile rapidly and economically. The method of this test is to strike the pile head  through a specific hammer by hand and use an instrument to  receive the refl ected wave. Through computer analysis to check the  abnormal conditions like crack, necking or soil inclusion, etc. This  testing method is usually used in PHC pile but now also used in cast  in-situ pile. 

1.2 (Pile Dynamic loading Test, DLT)

Dynamic loading test is a kind of quick, reliable and economically  method to test the capacity of pile. It is always used in diving pile,  bored pile and cast in-situ pile. Besides of capacity, DLT can also  provide the resistance distribution (pile and pile head) of soil, and  check integrity, quality and defects. DLT applies an axial impact  loading to a pile head, produce enough penetration to check the  stress of pile particle and the response of acceleration for real-time  analysis. The signal can be used for further analysis by computer  program (signal matching). Every DLT final report shall include  a simulation of static load result, to produce the curve of load –  settlement. 

1.3 (Static loading Test, SLT)

The method of Static loading test is to apply loads on the testing  pile using a large amount of concrete block or usually in reaction  pile system. After four cycles of loading and unloading processes,  measure the settlement and thus analysis the capacity of testing  pile. Strain gauges should be installed also at different depth  of testing pile for analyzing side friction of the foundation soil,  giving additional information for pile design works. High-accurate  8000KN or 10000KN Dynamometer WIGAbloc Elasto load cells  are used in the process of tests. 

1.4 Koden Test

Cast in-situ pile (Bored pile) shall be performed Koden test for  inspections of the diameter, verticality and bell-out diameter of the  pile hole. The method of Koden test is to drop down an instrument  along pile hole to the bottom. The instrument will transmit  ultrasonic wave to the pile wall and receive refl ected wave during  the drop down process. Diameter of testing pile hole should be from  0.5m to 4.0m and the depth should be 100m. NFP was in charge of  a large amount of Koden test of cast in-situ pile in Macau. 

1.5 (Cross-hole Sonic Logging Test, CSL)

The method of cross-hole sonic logging test is to plant several metal  pipe to a certain depth at a cast in-situ pile before concreting. After  concreted and 7 days age, drop down sensors at the same time to the  bottom through two metal pipes and then pull up. In this process,  the sensors will transmit ultrasonic wave and receive refl ected wave  to check the quality of concrete pile and analysis the completeness  of the pile. CSL is also available for inspection of completeness of  diaphragm wall also. 

1.6 (Anchor Pull-out Test)

In the construction of slope and retaining wall, there are two kinds  of anchor, rock anchor and soil anchor. After insert the anchor to a  designed depth and fi xed, use an instrument to apply a tension force  at the end of anchor. Through the elongation of the anchor, we can  assess the tensile strength, material and the construction quality.  Besides, usually there are some steel bars remain on the pile head to  connect superstructure in pile construction. Apply a tension force to  that steel bars also can assess the tensile strength, material and the  construction quality through the elongation. 

1.7 (Pneumatic Drill Test)

Pneumatic drill test is usually used to check the rock property. The  method of this test is to drill a drill pile to the rock layer through  certain compressed air pressure by Pneumatic drill machine.  Through the required time needed for drilling a certain depth to decide whether this rock layer can be the load-bearing layer.  Parameters of instrument of Pneumatic Drill Test normally are  35kg weight, 25mm diameter of pile or drill, 7bar compressed air  pressure. The required time of drilling 300mm depth of the rock  layer is less than 2 minutes. 

2.(Geological Site Investigation)

Center of foundation and prospecting - Geotechnical Department of  LECM, which is a prospecting centre with independent technique  and well experience on civil constructions and high quality in the  aspect of geological site investigation, providing geological site  investigation service and assessment on the geological parameters  for the kinds of future development project in Macau. Site  investigation is including in vertical drilling and inclined drilling  and environment boreholes with the depth more over 100m and  collecting samples of soil and rock and underground water for performing different kinds of laboratory tests. In-situ tests are  including the Standard Penetration Test, Cone Penetration Test,  Vane Shear Test, Soil and Rock Layer Permeability Test, Rock  Impression Packer Test etc. gINT software system is used to  integrate the geological information also. 

(Site Investigation Team)

2.1 Geological Boreholes

During the planning and design period of a project, it is necessary  to perform geological borehole around the site area to acquire  geological information for the designer. For 25 years recently, most  of the geological boreholes from government construction projects  have been completed be NFP of LECM such as Macau International  Airport project, Chinese People’s Liberation Army (PLA) Camp,  the new building of State Council of the People’s Republic of China  (CPG) in Macau, Sai Van Bridge of Macau, Stadiums for 2005 East  Asian Games, Macau LRT system project, tunnels project, Artifi cial  Island in Macau for Hong Kong-Zhuhai-Macao Bridge and  Reclamation Zone A and Zone B in Macau etc. Geological borehole  is to drill a hole vertically or a hole with inclination from ground  surface to investigate the thickness of soil/rock layers. Underground  water samples, soil and rock samples can be taken during the  geological drilling process. The physical parameters of the samples,  which are the important basis for the engineering planning and  design, can also be obtained by a series of laboratory tests.  

2.2 In-situ Tests

During the borehole drilling process, physical properties of soil  and rock strata can be measured by in-situ tests. General in-situ  tests for geological investigation include the Standard Penetration  Test (SPT), Cone Penetration Test (CPT), Vane Shear Test (VST),  Schmidt Hammer Rebound Test and Underground Water Pumping  Observation. 

2.3 Special In-situ Tests

For satisfying the design requirement of waterproofi ng (i.e. tunnel  and basement), the permeability of soil strata and rock strata and the  quantity and orientation of cracks in the rock layer can be measured  by special in-situ tests during the borehole drilling process.  Special in-situ tests for geological investigation include 1.In-Situ  Permeability Test for soil stratum and Packer Water Absorption Test  for rock stratum, 2.In-Situ Impression Packer Test. 

2.4 Field Inspection and Reception

NFP is the centre to inspect the drilling equipment, the methodology  of drilling, the terminated depth, category of soil, Total Core  Recovery (TCR), Rock Quality Designation (RQD) and the Grade  of the rock for the assessment on the quality of borehole and on that  whether the borehole complies with the requirement from designer.  In addition, when bored piles and diaphragm wall are completed,  interface core-drilling should be carried out at the concrete/rock  interface as the reception criteria of each pile and diaphragm wall  for the post construction proof drilling. 

2.5 Geological Analysis Report 

gINT software system is a geological analysis program, which  can provide an integrated geological report including borehole  log report, rock log, geological cross-section profile and analysis  chart of in-situ tests, based on the results from geological borehole  and in-situ tests. This geological report should be a very reliable  basis for the design of the project. Furthermore, all the geological  information can be integrated by gINT for the establishment of  Macau Geological Information Database.  

2.6 In-Situ Survey and Stakeout

Mobile GPS collector, which is used for staking out the locations  of boreholes based on the designed location before starting the  geological drilling works, and for surveying the coordinates and  the elevation of the boreholes after fi nishing the geological drilling  works. This GPS collector can connect to the data server of DSCC  for acquiring the correction for the Macau Coordinate System  through the 3G connection from CTM and perform the survey  works and stakeout works using the corrected Macau Coordinate  System.  

3.Geotechnical Monitoring

NFP is a centre providing geological monitoring services for  kinds of project (reclamations, tunnels, deep excavations, house  foundations and slopes) processing in Macau. Monitoring works  are including in: settlement of ground and deep soil layers, ground  displacement and lateral displacement of deep soil layers, pore  water pressure, underground water level, inclination monitoring of  structural foundation, strain monitoring of strut and waling system  and slope automatically monitoring, etc. Also the monitoring works  are related to the observation for the construction stage and the long  term safety observation after the construction, and the monitoring  results can be used to guide the safety construction and make the safety use of the facility. 

Geotechnical Monitoring Team in TAI TAM HILL for Slope Automatic Monitoring

3.1 Settlement and Displacement Observation

Settlements can be divided into ground surface settlement  (settlement point or settlement plate) and settlements of soil  stratum at different depths (Sondex casing installed by drilling),  and displacements can be divided into ground surface displacement  (displacement point) and displacements of soil stratum at different  depths (inclinometer casing installed by drilling). Settlement and  displacement observation must be considered item in a monitoring  plan for different kind of civil construction especially for the  reclamation project, tunnel project, deep excavation project and the  foundation project of buildings etc. 

3.2 Pore water pressure and underground water level

Pore water pressure observation is used to analyze the stable status of soil during consolidation of soil and during the period excavation  and backfilling. Underground water level observation, is used to  analyze the change of underground water level in soil strata because  it is an important parameter for the assessment on the settlement  of soil and for the design and construction of the structures under  the ground. The equipment for pore water pressure includes  open piezometer, pneumatic piezometer and electric piezometer.  Underground water level observation is to be monitored through  the excavation of water observation well and the installation of  standpipes. 

3.3 Strain Observation on Strut and Waling System

For the internal force observation on the strut and waling system  for deep excavation, it is usually to be installed, that the strain gage  is used to measure the strain value of the internal force, on the  strut and waling structure. The internal force of strut and waling  member can be calculated from the measured strain value based  on the material properties. Load Cell is the most effective method  for measuring the internal force of the strut and waling system.  Both strain gage and load cell can be connected to a data-logger to  measure the strut and waling system automatically.  

   (GK-403 Vibrating wire Readout)

3.4 Settlement and Inclination Observation for Structures

Settlement and inclination observation for structures around the  construction site (such as deep excavation, piling works and  backfi lling etc.) are usual in a monitoring plan. The normal method  for the settlement and observation for the structures is using  settlement marker which is installed on the structural member of  a building and then survey the elevation of the settlement marker  using leveling instrument. It is also to drill a borehole below the  ground and install an extensometer in the borehole to measure  the settlement of the structure using specified data acquirement  instrument or using automatic monitoring data-logger. 

Extensometer is used to measure the settlement of a structure

For the inclination observation of structures, Tiltplate and Tiltmeter  or Clinometer are the common instrument which are installed on  the structural member of building in Macau and they can also be  connected to the automatic monitoring data-logger. 

3.5 Slope Automatic Monitoring System

TAI TAM HILL is at East of Taipa, near by Macau International  Airport. For early years, it was a landfi ll with rubbish and stopped  operation in 1988 because of saturation of landfi ll. It was afforested  and reconstructed to public recreation area in 2001. Recently,  deformations on the slope, settlements and tension cracks on the  roads and existing buildings were found. Thus, LECM is the fi rst  to introduce the slope automatic monitoring system to perform the  slope monitoring and slope stability assessment for TAI TAM HILL. 

The location chart for monitoring instrument installed along each monitoring cross-section

Slope automatic monitoring system consists of three sub-system  (1) Monitoring Sensor System, (2) Data Acquirement System, (3)  Data Management System 

2 selected monitoring cross-section of Slope Automatic Monitoring System for TAI TAM HILL

Slope Automatic Monitoring System has the function that the data can be acquired and be charted by the system automatically

4.(Design and Analysis of Consolidation of Soft Soils)

NFP has the analysis ability of complex geotechnical engineering  problem. We can also perform a professional analysis for  consolidation of soft soils, dyke construction, reclamation and slope  stability, including calculation of settlement, consolidation and  capacity of soft soil, in the condition of reinforcement with sand  pile and drainage plate etc. Analysis of settlement and stability of  existing and new dyke are included also. At the present, NFP has in  charged and fi nished the design of soft soils foundation treatment in  the general medical facilities of SSM in Coloane, and the analysis  of stability of the vertical dyke in Fai Chi Kei, Macau.