9 Supervision and monitoring

9.1 Supervision

9.1.1 A suitably qualified and experienced person shall be in charge of the execution of the work.

9.1.2 The person in charge shall be responsible for:

• the conformity of the work with this European Standard and with any additional specification and agreed working procedure;
• the monitoring of pile construction and keeping of all necessary records; and to
• keep the client's representative and/or the designer informed of any variations or deviations from the expected situation or condition of the site or any cases of non conformity.

9.2 Monitoring of pile construction

9.2.1 The specific procedures for verification, control and acceptance shall be established before the commencement of the works.

9.2.2 The pile construction process shall be monitored and all relevant data shall be recorded, including:

• setting out, pile type, dimensions and depths;
• excavation procedure, tools and equipment;
• installation of casings;
• stratification of ground and groundwater levels;
• obstructions;
• use of a stabilizing fluid;
• levels of water or of stabilizing fluid in the pile bore;
• construction of pile sockets;
• construction and control of enlargements;
• cleaning of pile bore;
• checks of stabilizing fluid;
• reinforcements type, dimensions, assembly and length;
• reinforcement installation depth and position;
• installation of precast concrete elements or reinforcement tubes or sections;
• concreting in submerged or dry conditions;
• concreting of continuous flight auger piles;
• site mixed or ready-mixed concrete;
• concrete grade, composition and consistency;
• concrete placement, quantity, duration, rise and final elevation;
• recovery of temporary casings;
• recovery of the tremie pipe;
• shaft and/or base grouting: mix composition and properties, zone of application, time, supply rate, pressure and quantity.

9.2.3 The duration's of the respective operations should also be recorded.

9.2.4 All non conformance's shall be notified.

9.2.5 During excavation, the ground behaviour shall be observed and any unforeseen change or feature that might be important for the design shall be communicated to the supervisor and the designer.

NOTE: Examples of the details and frequencies for the monitoring are given in tables 6 to 15.

9.2.6 The records shall be submitted to the client's representative and/or to the designer and shall be signed as agreed.

NOTE: Records are dealt with in clause 10, Sample records are provided in annex B.

9.2.7 After preparation of the piles for their structural use, an "as built" record plan shall be drawn up showing positions and dimensions of piles together with pile head and founding levels.

9.2.8 The record plan, the pile monitoring records and any other piling documentation shall be kept as required by the contract and/or the statutory requirements.

	Subject	Control	Purpose	Frequency	Remarks
1	main axes	survey	setting out of piles	at commencement of works	establishment of main axes for time of execution
2	working platform	survey, visual check	elevation, level ness, size, stability	each construction area
3	- pile position, - pile rake	survey - plumb-line - tape - spirit level	check of deviations against geometrical construction tolerances	every pile - before start of excavation - after excavation - after completition

	Subject	Control	Purpose	Frequency	Remarks
1	lead-in tube (guide wall)	- diameter - width - depth	- stability of top of uncased excavations - conformity with the design	each pile	can be omitted for circular piles with D < 0,6 m
2	condition and dimensions of tools, casings	- visual check - measurement	adequacy	before and during use (as applicable)
3	use of tools, (general)	- progress of excavation - efficiency - over excavation	- supervision - recognition of (changing) ground conditions - depth - times - tool changes	continuously
4	use of tools, (submerged)	as above, plus - operation speed	avoid piston effect	continuously
5	casing installation	measurement	advance of casing during excavation	continuously	particularly important when casing advance ahead of excavation is necessary
6	water level	measurement	stability of pile bore	continuously
7	excavated material	visual check	recognition of - strata and - soil variations	continuously	samples to be kept as necessary
8	pile depth (completion of excavation)	measurement: - depth - slope (measurement of inclined bearinq strata)	achievement of specified depth	each pile	verification can also be effected with calibrated tool
9	enlargement	measurement (by operational control of equipment) (visual inspection)	- size - slope of walls - alignment	each enlargement	measurement preferred through calibrated equipment
10	cleaning of base	- grab - sounding - (visual inspection)	- clean interface to bearing stratum - pile performance	each pile
11	standing water on base	- tape - visual inspection	avoid segregation and contamination of concrete	each pile

	Subject	Control	Purpose	Frequency	Remarks
1	supply, storage	check	supply in line with consumption	continuously	supply/storage should cater for sudden loss
2	level in pile bore	check	stability of hole	continuously
3	properties of suspension	- density - consistency (Marsh value) - fluid loss - alkalinity - sand content	conformity - with 6.5.2 and 6.5.3 or - national standards	each pile fresh fluid - before concreting - after desanding, before reuse

	Subject	Control	Purpose	Frequency	Remarks
1	delivery of materials	- delivery documents - dimensions	conformity	each delivery
2	dimensions	measurement	conformity	spot check
3	fabrication of cages	- dimensions - spacing of longitudinal bars - spacing of transverse bars - fixing - rigidity	conformity	each cage	where welding is carried out: check in accordance with the specification for the reinforcing steel
4	spacers	- material - size - quantity - distribution	- conformity - deviation of installation	each cage	inner dimension of the casing (if any) to be taken into account
5	installation of cages	- survey - measurement	deviation of installation	each cage
6	reinforcement tube/ steel section	- survey - measurement	deviation of installation	each tube or section
7	special reinforcement	accordance to special procedure	conformity	accordance to special procedure
8	embedment - pipes for sonic coring - monitoring devices - box-outs	- position - depth - connections with cage - protection during installation - protection during concrete placement	- conformity - reliability	each cage

	Subject	Control	Purpose	Frequency	Remarks
1	continuity of supply	check	continuity of placement	before placement
2	concrete - grade - composition	delivery document	conformity	each truck
3	consistence	- slump or - flow table	- conformity - workability	- each truck (truck delivery) or - every 10 m3
4	ambient temperature	thermometer	protection of newly cast piles	when required
5	concrete temperature	thermometer	- conformity - workability	when required	frequency to be increased when in doubt
6	workability time	workability check on fresh concrete	check of duration of workability	- when required or - in doubt	test is carried out in parallel to concrete placement

	Subject	Control	Purpose	Frequency	Remarks
1	concreting pipe, tremie pipe - conditions	visual check	- cleanliness - watertightness - internal smoothness	each pipe before or during installation
2	- internal diameter - external dimensions	check/ measurement	- compatibility with aggregate sizes - free movement inside reinforcement	- each set of pipes - each size of pile
3	- composition (sectional lengths)	check/ measurement	preparation for recovery	each set of pipes
4	- installation depth	measurement	avoid segregation at commencement of concrete placement	each pile	tremie pipe should rest on the bottom
5	- separation of concrete from water inside tremie pipe	check	avoid segregation	each pile	use e.g. of - bottom lid - ball or - plastic chips
6	- immersion of tremie pipe during concreting and recovery	check depth of concrete against length of tremie pipe	- maintenance of sufficient immersion - avoid segregation - avoid contamination of the concrete	continuously	- sufficient immersion also during recovery of tremie pipes - observe any accumulating water inside the tremie pipe
7	immersion of casing during recovery	check depth of concrete against tip of casing	- maintenance of sufficient of immersion - avoid necking - avoid segregation and contamination of concrete	continuously	observe any sudden drop or rise of concrete
8	casting level	depth measurement	sufficient height above cut-off level	each pile
9	backfilling empty bore	check	site safety	each pile
10	concrete volume	compare consumption with theoretical excavation volume	detect excessive overbreak or necking	each pile (where possible)	detailed monitoring, including records of concrete slump during casing recovery, can be necessary
11	pile head after casting	visual check	detect excessive water flow	each pile (where possible)	some bleeding will always result from self compaction of the concrete; excessive bleeding might be an indication of possible shaft inclusions

	Subject	Control	Purpose	Frequency	Remarks
1	conditions and dimensions of - auger - cutting head - closure device	- visual check - measurements	adequacy	before commencement of boring
2	excavation process	check - speed of rotation and of - penetration	limit over excavation	continuously
3	excavation depth / founding layer	check - speed of rotation - penetration - torque (optional) - material - depth	conformity	each pile	some information may be relative and not conclusive
4	commencement of concreting	check concrete flow	check for blockage	each pile
5	concreting	check - concrete pressure - concrete flow and - consumption corresponding auger withdrawal	complete filling of bore with concrete	each pile, continuously

	Subject	Control	Purpose	Frequency	Remarks
1	cleanliness of excavation	check, measurement (tape with plumb bob)	interface of pile to bearing stratum	each pile
2	grouting pipes	- diameter - number - installation depth	provision for the grouting process	each pile	site trials recommended for the verification of the spread of grout and the distribution of grouting pipes
3	aggregate	- size - quantity	filling complete volume	each pile
4	grout properties	- composition - consistence - workability time (setting time) - bleeding - admixtures	- workability - strength	each batch
5	grouting process	- pumping rate - pressure - consumption - withdrawal of grouting pipes	- proper grout distribution - provision of continuous shaft	each pile, continuously
6	grout strength	compressive strength	conformity with specification	each pile

	Subject	Control	Purpose	Frequency	Remarks
1	grouting pipes	- diameter - number - distribution - installation depth - fixing to reinforcement cage - arrangement of valves	conformity with special method statement	each pile
2	(flexible) box structure	- area - contact to base of excavation - sealing to concrete column above - fixing to cage - function and fixing of grouting and vent pipes	- maintenance of void after concrete placement - check apparatus before installation	each pile
3	grouting process	- pumping rate - pressure - consumption - distribution of grout	proper distribution of grout	each pile, continuously

	Subject	Control	Purpose	Frequency	Remarks
1	concrete at cut-off level	visual check - concrete quality - pile section - evenness - existence of cracks - condition of reinforcement - concrete cover	provide satisfactory conditions for connection of pile to superstructure	each pile	If concrete quality is found to be inadequate at the design cut-off level, the pile is to be cut further down and to be reconcreted after the formation of a construction joint.

9.3 Pile testing

9.3.1 General

NOTE 1: The principal requirements for pile testing are contained in ENV 1997-1. The following notes contain general remarks, which may be supplemented by national application documents, as applicable (as long as respective European Standards are not available).

NOTE 2: Pile tests may be used for research or investigation purposes for proof of:

• resistance/deformation characteristics in the general range of specified actions;
• the soundness and proper construction of a pile.

NOTE 3: Pile tests can consist of (see clause 3):

• maintained load tests;
• constant rate of penetration tests;
• dynamic pile tests for the determination of the pile capacity; and
• integrity tests which measure the acoustic or vibrator properties of the pile in order to determine the presence of possible anomalies within the pile body.

NOTE 4: The application of various procedures is as indicated in table 16 below. Definitions of the different tests are provided in clause 3.

Type of test	Application
	Proof of ultimate pile resistance	Proof of working deformation range	Structural soundness (integrity)
Maintained load pile test	yes	yes	sometimes possible 1)
Continuous rate of penetration test	yes 1)	indicative for non-cohesive ground if slow enough	no
dynamic pile test	yes 1)	possible 1)	yes 1)
Integrity test	no 1)	no	yes 1)
1) Subject to interpretation

NOTE 5: The only test which can derive the ultimate resistance directly is the maintained load test if loads are sufficient and held constant for a long enough period. Other tests require subsequent interpretation. Similarly, dynamic testing methods cannot measure consolidation or creep under load. Any approximations made to the results for the purpose of establishing load/settlement relationships should therefore be made clear in test reports.

9.3.2 Axial loading tests

9.3.2.1 The strength of the pile shall be such that at the time of testing, its structure will not be damaged.

9.3.2.2 Additional material strength testing can be necessary for this purpose.

9.3.2.3 In maintained load tests and constant rate of penetration tests, the pile head displacements in the direction of the load shall be determined by at least two measuring devices, the accuracy of which shall be at least 0,1 mm.

9.3.2.4 The transverse displacements of the pile head should also be measured.

9.3.2.5 In maintained load tests, loads should be maintained constant at each of at least 6 stages for a specified duration. Unless otherwise agreed the displacement rate should be less than 0,1 mm/20 min at the end of each stage.

9.3.2.6 In continuous rate of penetration tests the rate of displacement shall be kept constant at approximately 1 mm / min throughout the period of the test.

9.3.2.7 Other rates of displacement may be agreed prior to testing.

9.3.2.8 During each test there should be at least two independent measuring devices for load and they should check against each other to exclude gross errors.

9.3.2.9 All force measuring devices shall be calibrated at least once annually. As long as European Standards are not available different national requirements or specifications shall be observed.

9.3.2.10 For dynamic load tests the pile shall be allowed to gain sufficient strength after installation and before testing.

9.3.2.11 Dynamic and integrity tests shall be carried out using equipment built and approved for the purpose and are required to be interpreted by persons competent in this area who shall also have a knowledge of the techniques of piling and experience of the specific ground conditions.

9.3.2.12 The apparatus shall be used in accordance with the manufacturer's instructions and the pile shall be prepared for the purpose of testing in an appropriate manner.

9.3.2.13 In tests where the load is directly applied to the pile, either using kentledge, ground anchors or anchorage piles, the loading arrangements shall be such that the equipment remains stable and does not bring about soil displacements liable to change considerably the behaviour of the pile.

9.3.2.14 The supports or anchorages of a reaction system should observe the following minimum clear distances to the test pile:

• a) supports of kentledge: a ≥ 3 × D
• b) bond lengths of vertical anchorages: a ≥ 3 × D and a ≥ 3,0 m;
• c) bond lengths of inclined anchorages: a ≥ 5 × D and a ≥ 5,0 m.

9.3.2.15 On completion of tests the results, together with full details of the pile tested, its location and a summary of ground conditions, shall be presented without undue delay in a report to the employer, using graphical and numerical form where appropriate.

9.3.2.16 Where rapid loading has been applied, full correlation data with maintained load tests in similar ground shall be provided.

10 Records

10.1 The site records shall consist of two parts; the first making reference to the site and the general information including:

• the pile (type, dimensions...);
• the construction method; and
• the reinforcement and concrete specification.

The second part shall contain particular information related to the construction procedure.

10.2 The general information part shall be similar for the different types of piles and methods and shall contain the details listed in table 17 and table 18.

10.3 The particular information part shall be specific to thes type of pile and the construction method and shall contain the details listed in table 19.

10.4 As appropriate, the information can be provided in the form of

• individual records compiled for each pile, or
• summary records for groups of piles of the same type, constructed with the same method.

10.5 Details of recording and the format of the site records shall be agreed before the commencement of the piling.

NOTE: Sample construction records are provided in Annex B.

	Subject	necessity
1	site location	X
2	contract identification	X
3	structure	X
4	main contractor	(X)
5	foundation (piling) contractor	X
6	client/employer	(X)
7	engineer / designer	(X)
X      necessary information
(X)   information as applicable

	Subject	necessity
1	pile diameter/size/enlargements	X
2	excavation method	X
3	details of stabilizing fluid	X
4	cleaning method	X
5	reinforcement details	X
6	concrete specification	X
7	concrete placement details	X
X   necessary information

10.6 Records of any integrity testing shall provide

• the reason for the testing,
• the testing method and procedure,
• the test results, and
• the conclusions on the pile integrity.

NOTE: Recording requirements for static or dynamic load testing and the format of the load test report are provided in ENV 1997-1.

10.7 All records shall be signed by the contractor's representative and by the client's representative unless otherwise agreed.

Nr	Subject	cased/uncased excavation	excavation supported by fluids	continuous flight auger piles
1	pile reference number	X	X	X
2	excavation times	X	X	X
3	interruptions of excavation	X	X	X
4	removal of obstructions	X	X	—
5	temporary/permanent casing	X	—	—
6	depth of casing	X	—	—
7	lead in tube/guide wall	—	X	(X)
8	depth of lead in tube	—	X	(X)
9	depth of pile	X	X	X
10	stratification log	X	X	(X)
11	ground water table	X	X	(X)
12	cleaning	X	X	—
13	stabilizing fluid - properties	—	X	—
14	- recovery	—	X	—
15	reinforcement - length	X	X	X
16	- suspension	X	X	X
17	- installation time	X	X	X
18	concrete placement - dry/submerged conditions	X	X	—
19	- duration	X	X	X
20	- interruptions	X	X	X
21	- volume	X	X	X
22	- pressure	—	—	X
23	- site tests	X	X	X
24	recovery of casing	X	—	—
25	recovery of lead in tube	—	X	(X)
26	backfilling empty bore	X	X	X
27	precast concrete elements - type and details	X	X	—
28	- installation	X	X	—
29	- external grouting process	X	X	—
30	- properties of self hardening slurry	X	X	—
31	- suspension	X	X	—
32	- cover	X	X	—
33	external grouting - details of grouting pipes/box structure	X	X	(X)
34	- grout properties	X	X	(X)
35	- grouting process	X	X	(X)
36	prepacked piles - details of aggregate	X	—	—
37	- details of grouting system		—	—
38	- grout properties	X	—	—
39	- grouting process of bore	X	—	—
40	shaft and base grouting - grouted area	X	X	X
41	- details of grouting system	X	X	X
42	- grout properties	X	X	X
43	- grouting process	X	X	X
44	construction deviations - position	X	X	X
45	- rake	X	X	X
X necessary information (X) information as applicable — not applicable

11 Specific Requirements

11.1 Regarding:

• safety on the site;
• safety of the working practices;
• legality of manual works and inspections inside excavations; and
• operational safety of piling and auxiliary equipment and tools;

the respective national standards, specifications or statutory requirements regarding execution of bored piling works shall be observed, as long as respective European Standards are not available.

11.2 Equipment shall be in accordance with EN 791.

11.3 Particular attention shall be drawn to

• all processes requiring men operating alongside heavy equipment and heavy tools,
• the danger of open holes,
• manual working procedures and inspections carried out inside excavations.

11.4 Excavation by hand should be kept to a minimum.

11.5 Excavation by hand shall be restricted to dry conditions where the ground is naturally stable or where support of the excavation walls is continuously be maintained.

11.6 Employment of personnel inside a bore is permitted only if the available space for the work is at least 0,75 m in diameter.

11.7 Nuisance and/or environmental damage that can be caused by the piling work shall be kept to a minimum.

11.8 Such nuisance and/or environmental damage can be caused by:

• noise;
• ground vibration;
• ground pollution;
• surface water pollution;
• groundwater pollution; and
• air pollution.

NOTE: The kind and extent of possible nuisance or environmental impact depends on:

• the location;
• the working method;
• the actual processes.

11.9 Regarding nuisance and environmental protection, for each particular situation

• the national requirements (as long as respective European Standards are not available), and
• the local requirements shall be observed.