CBC · California Building Code

When must a geotechnical representative continuously observe pile installation?

If your project uses driven piles, the California Building Code requires a qualified geotechnical engineer’s representative to be on site for the entire pile‑driving operation, keep detailed driving and equipment records, and submit a report (including dynamic‑test data if used) to the enforcement agency.

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Last reviewed: July 5, 2026

What the code requires — 2–4 sentences

The California Building Code requires that the installation of driven deep foundations (driven piles) be continuously observed by a qualified representative of the project geotechnical engineer. This continuous observation requirement and the required reporting items are stated in § 1705.7.1 and implemented through the driven-foundation special‑inspection table in § 1705.7.

Requirements in detail

Who must observe

A qualified representative of the geotechnical engineer responsible for that portion of the project must continuously observe installation of driven deep foundations; the CBC text uses that phrase exactly (i.e., "continuously observed by a qualified representative of the geotechnical engineer"). § 1705.7.1 / § 1705A.7.1.

What "continuous observation" triggers and what to record

The code couples the continuous observation requirement with a list of items that the observer must verify and record. Table 1705.7 (driven elements) and § 1705.7.1 spell out what must be inspected/recorded and reported, including:

verification of element materials, sizes and lengths;
inspection of driving operations and complete records for each element;
verification of placement locations and plumbness; confirmation of type and size of hammer and recording blows per foot;
determination/recording of required penetration to achieve design capacity and tip/butt elevations; and
when allowable pile loads are determined using a dynamic formula, the observer must report the design formula used and the permanent penetration under the last 10 blows. § 1705.7 and § 1705.7.1.

One copy of the geotechnical representative’s report on the pile‑driving operation must be submitted to the enforcement agency, per § 1705.7.1.

Minimum duties and final reporting

The representative’s report must include equipment characteristics, identifying marks for each pile, total embedment depth for each pile, and the dynamic‑test data/details when applicable (formula used and last 10‑blow permanent penetration). § 1705.7.1.
The approved geotechnical report and the registered design professionals’ construction documents are to be used to determine compliance with inspection details and acceptance criteria. § 1705.7.

Decision‑relevant table

Decision factor	What the code requires	Typical value / action	Code Reference
Element type	Driven deep foundation elements require continuous observation	Continuous on‑site observation during driving	§ 1705.7
Observer	Must be a qualified representative of the geotechnical engineer	Geotechnical rep on site for duration of driving	§ 1705.7.1 / § 1705A.7.1
Records — equipment & ID	Physical characteristics of driving equipment and identifying marks for each pile	Record hammer type/size, pile ID, tip/butt elevations	§ 1705.7.1 / Table 1705.7 items 3–4
Records — driving data	Number of blows per foot; permanent penetration (last 10 blows) when dynamic formula used	Record blows/ft continuously; report permanent penetration under last 10 blows if used	§ 1705.7; § 1705.7.1
Reporting	Report to enforcement agency; use geotechnical & construction documents for compliance	One copy of the geotechnical rep’s pile‑driving report to enforcement agency	§ 1705.7.1

Exceptions & special cases

Cast‑in‑place deep foundations: different continuous‑inspection requirements and checklists apply (see Table 1705.8 / § 1705.8). The procedures for cast‑in‑place elements are handled under the cast‑in‑place deep‑foundation section, not § 1705.7 for driven piles. § 1705.8 / Table 1705.8.
Helical piles: the CBC explicitly requires continuous special inspection during helical pile installation and records tailored to helical systems (installation torque, tip elevations, final depth, etc.) under § 1705A.9 / § 1705.9. This is a separate continuous‑inspection requirement specific to helical piles. § 1705A.9 / § 1705.9.
Dynamic formula use: when allowable pile capacity is derived from dynamic testing (driving records), the representative must record and report the design formula and the permanent penetration under the last 10 blows. This is a mandatory reporting item specific to driven piles. § 1705.7.1.

Note: the code text requires "continuous" observation but does not, in the sections retrieved, define a numeric minimum (for example, minutes per day or response time) for “continuous.” Jurisdictions or the building official commonly interpret and apply that phrase in practice (local enforcement may specify expectations). The CBC text cited here does not provide an explicit time‑window definition for "continuous."

Common mistakes

Treating "periodic" special inspection as satisfying the requirement for driven piles — Table 1705.7 explicitly lists driven pile items as continuous special inspection; do not substitute periodic checks. § 1705.7.
Omitting required dynamic‑test reporting when allowable loads come from a dynamic formula (failing to include the formula used and the permanent penetration under the last 10 blows). § 1705.7.1.
Having a special inspector (construction/structural) perform the observation when the code requires a qualified representative of the geotechnical engineer to continuously observe driven‑pile installation. Verify the statement of special inspections and the geotechnical engineer of record. § 1705.7.1.
Failing to send one copy of the geotechnical representative’s pile driving report to the enforcement agency as required. § 1705.7.1.

Worked example — concrete scenario

Scenario: A project installs driven steel H‑piles to 40 ft embedment. The design uses a dynamic pile‑driving analysis to establish allowable pile loads.

What the geotechnical representative must do on site:

Continuously observe each driving operation from the start of driving until the element is complete (continuous presence during driving) per § 1705.7.1.
Record pile identifying mark (e.g., P‑12), pile tip elevation and butt elevation, and total embedment (40 ft), and the physical characteristics of the hammer (make, model, rated energy). See Table 1705.7 required records. § 1705.7.
During driving, record blows per foot. Suppose the last 10 blows produced a cumulative penetration of 2.5 inches; the "permanent penetration under the last 10 blows" is therefore 2.5 in and must be reported if the allowable capacity is determined by a dynamic formula. (Report the dynamic design formula used, e.g., CAPWAP or an approved engineering formula, as required by § 1705.7.1.)
Prepare and send one copy of the geotechnical representative’s report including all above data to the enforcement agency. § 1705.7.1.

This example follows the code requirements for records and reporting in § 1705.7 and § 1705.7.1.

Related provisions

§ 1705.7 — Driven deep foundations; required continuous inspection items and Table 1705.7.
§ 1705.7.1 / § 1705A.7.1 — Driven deep foundations observation; continuous observation and reporting requirements.
§ 1705.8 / § 1705A.8 — Cast‑in‑place deep foundations; continuous inspections and Table 1705.8 (different checklist).
§ 1705.9 / § 1705A.9 — Helical pile foundations; continuous inspections and specific records (torque, final depth, tip elevation).
§ 1705.10 / § 1705A.10 — Structural integrity of deep foundation elements; engineering assessment and defect testing procedures.

Code references

Grounded in the retrieved California Building Code — click a citation to read the verbatim passage:

CBC § 0.01 High relevance — show source text
**_ 1. The shoring design engineer or his designee shall make periodic inspections of the job site for the purpose of observing the installation of the shoring system, testing of tie-back anchors and monitoring of the survey. 2. Testing, inspection and observation shall be in accordance with testing, inspection and observation requirements approved by the building official. The following activities and materials shall be tested, inspected or observed by the special inspector and geotechnical engineer: a. Sampling and testing of concrete in soldier pile and tie-back anchor shafts. b. Fabrication of tie-back anchor pockets on soldier beams c. Installation and testing of tie-back anchors. d. Survey monitoring of soldier pile and tie-back load cells. e. Survey monitoring of existing buildings. 3. A complete and accurate record of all soldier pile locations, depths, concrete strengths, tie-back locations and lengths, tie-back grout strength, quantity of concrete per pile, quantity of grout per tie-back and applied tie-back loads shall be maintained by the special inspector and geotechnical engineer. The shoring design engineer shall be notified of any unusual conditions encountered during installation. 4. Calibration data for each test jack, pressure gauge and master pressure gauge shall be verified by the special inspector and geotechnical engineer. The calibration tests shall be performed by an independent testing laboratory and within 120 calendar days of the data submitted. 5. Monitoring points shall be established at the top and at the anchor heads of selected soldier piles and at intermediate intervals as considered appropriate by the geotechnical engineer. 6. Control points shall be established outside the area of influence of the shoring system to ensure the accuracy of the monitoring readings. 7. The periodic basis of shoring monitoring, at a minimum, shall be as follows: a. Initial monitoring shall be performed prior to any excavation. b. Once excavation has begun, the periodic readings shall be taken weekly until excavation reaches the estimated subgrade elevation and the permanent foundation is complete. c. If performance of the shoring is within established guidelines, shoring design engineer may permit the periodic readings to be biweekly. Once initiated, biweekly readings shall continue until the building slab at ground floor level is completed and capable of transmitting lateral loads to the permanent structure. Thereafter, readings can be monthly. d. Where the building has been designed to resist lateral earth pressures, the periodic monitoring of the soldier piles and adjacent structure can be discontinued once the ground floor diaphragm and subterranean portion of the structure is capable of resisting lateral soil loads and approved by the shoring design engineer, geotechnical engineer and the build- ing official. e. Additional readings shall be taken when requested by special inspector, shoring design engineer, geotechnical engineer or the building official. 8. Monitoring readings shall be submitted to shoring design engineer, engineer in responsible charge, and the building official within 3 working days after they are conducted. Monitoring readings shall be accurate to within 0.01 feet. Results are to be submitted in tabular form showing at least the initial date of monitoring and reading, current monitoring date and reading and difference between the two readings. 9. If the total cumulative horizontal or vertical movement (from start of construction) of the existing buildings reaches [1] / 2 inch or _soldier piles movement reaches 1 inch all excavation activities shall be suspended.

CBC § 17A-15 High relevance — show source text

For steel elements, perform additional special inspections in accordance with Section 1705_A_.2.|In accordance with Section 1705_A_.2|In accordance with Section 1705_A_.2| |6. For concrete elements and concrete-filled elements, perform tests and additional special
inspections in accordance with Section 1705_A_.3.|In accordance with Section 1705_A_.3|In accordance with Section 1705_A_.3| |7. For specialty elements, perform additional inspections as determined by the registered design
professional in responsible charge.|In accordance with Statement of Special
Inspections|In accordance with Statement of Special
Inspections|

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1705A.7.1 Driven deep foundations observation. The installation of driven deep foundations shall be continuously observed by a qualified representative of the geotechnical engineer responsible for that portion of the project.

The representative of the geotechnical engineer shall make a report of the deep foundation pile-driving operation giving such pertinent data as the physical characteristics of the deep foundation pile-driving equipment, identifying marks for each deep founda- tion pile, total depth of embedment for each deep foundation; and when the allowable deep foundation pile loads are determined by a dynamic load formula, the design formula used, and the permanent penetration under the last 10 blows. One copy of the report shall be sent to the enforcement agency.

1705 A .8 Cast-in-place deep foundations. Special inspections and tests shall be performed during installation of cast-in-place deep foundation elements as specified in 1810A.3.3.1.2 and Table 1705 A .8. The approved geotechnical report and the construction documents prepared by the registered design professionals shall be used to determine compliance.

TABLE 1705A.8—REQUIRED SPECIAL INSPECTIONS AND TESTS OF CAST-IN-PLACE DEEP FOUNDATION ELEMENTS	Col2	Col3
TYPE	CONTINUOUS SPECIAL INSPECTION	PERIODIC SPECIAL INSPECTION
1. Inspect drilling operations and maintain complete and accurate records for each element.	X	—
2. Verify placement locations and plumbness, confirm element diameters, bell diameters (if applicable), lengths, embedment into bedrock (if applicable) and adequate end-bearing strata capacity. Record concrete or grout volumes.	X	—
3. For concrete elements, perform tests and additional special inspections in accordance with Section 1705_A_.3.	In accordance with Section 1705_A_.3	In accordance with Section 1705_A_.3

�

1705A.8.1 Micropile tests. Micropile preproduction and production load tests shall be in accordance with Section 1810A.3.10.4.

1705 A .9 Helical pile foundations. Continuous special inspections shall be performed during installation of helical pile foundations. The information recorded shall include installation equipment used, pile dimensions, tip elevations, final depth, final installation torque and other pertinent installation data as required by the registered design professional in responsible charge. The approved geotechnical report and the construction documents prepared by the registered design professional shall be used to determine compliance.

CBC § 1705.2. High relevance — show source text

Inspect driving operations and maintain complete and accurate records for each element.|X|—| |4. Verify placement locations and plumbness, confirm type and size of hammer, record number
of blows per foot of penetration, determine required penetrations to achieve design capacity,
record tip and butt elevations and document any damage to foundation element.|X|—| |5. For steel elements, perform additional special inspections in accordance with Section 1705.2.|In accordance with Section 1705.2|In accordance with Section 1705.2| |6. For concrete elements and concrete-filled elements, perform tests and additional special
inspections in accordance with Section 1705.3.|In accordance with Section 1705.3|In accordance with Section 1705.3| |7.For specialty elements, perform additional inspections as determined by the registered design
professional in responsible charge.|In accordance with Statement of Special
Inspections|In accordance with Statement of Special
Inspections|

1705.7.1 Driven deep foundations observation. [OSHPD 1R, 2 & 5] The installation of driven deep foundations shall be continu- ously observed by a qualified representative of the geotechnical engineer responsible for that portion of the project.

1705.8 Cast-in-place deep foundations. Special inspections and tests shall be performed during installation of cast-in-place deep foundation elements as specified in Table 1705.8. The approved geotechnical report and the construction documents prepared by the registered design professionals shall be used to determine compliance.

TABLE 1705.8—REQUIRED SPECIAL INSPECTIONS AND TESTS OF CAST-IN-PLACE DEEP FOUNDATION ELEMENTS	Col2	Col3
TYPE	CONTINUOUS SPECIAL INSPECTION	PERIODIC SPECIAL INSPECTION
1. Inspect drilling operations and maintain complete and accurate records for each element.	X	—
2. Verify placement locations and plumbness, confirm element diameters, bell diameters (if applicable), lengths, embedment into bedrock (if applicable) and adequate end-bearing strata capacity. Record concrete or grout volumes.	X	—
3. For concrete elements, perform tests and additional special inspections in accordance with Section 1705.3.	In accordance with Section 1705.3	In accordance with Section 1705.3

1705.9 Helical pile foundations. Continuous special inspections shall be performed during installation of helical pile foundations. The information recorded shall include installation equipment used, pile dimensions, tip elevations, final depth, final installation torque and other pertinent installation data as required by the registered design professional in responsible charge. The approved

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geotechnical report and the construction documents prepared by the registered design professional shall be used to determine compliance.

CBC § 1705.7 High relevance — show source text

The duties of the geotechnical engineer or his or her qualified representative shall include, but need not be limited to, the inspec- tion of cleared areas and benches prepared to receive fill; inspection of the removal of all unsuitable soils and other materials; the approval of soils to be used as fill material; the inspection of placement and compaction of fill materials; the testing of the completed fills; and the inspection or review of geotechnical drainage devices, buttress fills or other similar protective measures in accordance with the approved construction documents.

A verified report shall be submitted by the geotechnical engineer as required by the California Administrative Code. The report shall indicate that all tests and inspections required by the approved construction documents were completed and whether the tested materials and/or inspected work meet the requirements of the approved construction documents.

1705.7 Driven deep foundations. Special inspections and tests shall be performed during installation of driven deep foundation elements as specified in Table 1705.7. The approved geotechnical report and the construction documents prepared by the registered design professionals shall be used to determine compliance.

TABLE 1705.7—REQUIRED SPECIAL INSPECTIONS AND TESTS OF DRIVEN DEEP FOUNDATION ELEMENTS	Col2	Col3
TYPE	CONTINUOUS SPECIAL INSPECTION	PERIODIC SPECIAL INSPECTION
1. Verify element materials, sizes and lengths comply with the requirements.	X	—
2. Determine capacities of test elements and conduct additional load tests, as required.	X	—
3. Inspect driving operations and maintain complete and accurate records for each element.	X	—
4. Verify placement locations and plumbness, confirm type and size of hammer, record number of blows per foot of penetration, determine required penetrations to achieve design capacity, record tip and butt elevations and document any damage to foundation element.	X	—
5. For steel elements, perform additional special inspections in accordance with Section 1705.2.	In accordance with Section 1705.2	In accordance with Section 1705.2
6. For concrete elements and concrete-filled elements, perform tests and additional special inspections in accordance with Section 1705.3.	In accordance with Section 1705.3	In accordance with Section 1705.3
7.For specialty elements, perform additional inspections as determined by the registered design professional in responsible charge.	In accordance with Statement of Special Inspections	In accordance with Statement of Special Inspections

CBC § 1705A.6.2 High relevance — show source text

1705A.6.2 Earth-retaining shoring. Special inspections and tests of earth-retaining shoring shall be in accordance with applicable portions of Section 1812A.

1705A.6.3 Vibro stone columns. Special inspections and tests of vibro stone columns for ground improvement shall be in accordance with Section 1813A.5.

1705 A .7 Driven deep foundations. Special inspections and tests shall be performed during installation of driven deep foundation elements as specified in 1810A.3.3.1.2 and Table 1705 A .7. The approved geotechnical report and the construction documents prepared by the registered design professionals shall be used to determine compliance.

TABLE 1705A.7—REQUIRED SPECIAL INSPECTIONS AND TESTS OF DRIVEN DEEP FOUNDATION ELEMENTS	Col2	Col3
TYPE	CONTINUOUS SPECIAL INSPECTION	PERIODIC SPECIAL INSPECTION
1. Verify element materials, sizes and lengths comply with the requirements.	X	—
2. Determine capacities of test elements and conduct additional load tests, as required.	X	—
3. Inspect driving operations and maintain complete and accurate records for each element.	X	—
4. Verify placement locations and plumbness, confirm type and size of hammer, record number of blows per foot of penetration, determine required penetrations to achieve design capacity, record tip and butt elevations and document any damage to foundation element.	X	—
5. For steel elements, perform additional special inspections in accordance with Section 1705_A_.2.	In accordance with Section 1705_A_.2	In accordance with Section 1705_A_.2
6. For concrete elements and concrete-filled elements, perform tests and additional special inspections in accordance with Section 1705_A_.3.	In accordance with Section 1705_A_.3	In accordance with Section 1705_A_.3
7. For specialty elements, perform additional inspections as determined by the registered design professional in responsible charge.	In accordance with Statement of Special Inspections	In accordance with Statement of Special Inspections

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CBC § 18A-27 High relevance — show source text
2025 CALIFORNIA BUILDING CODE 18A-27

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3. A complete and accurate record of all soldier pile locations, depths, concrete strengths, tie-back locations and lengths, tie-back grout strength, quantity of concrete per pile, quantity of grout per tie-back and applied tie-back loads shall be maintained by the special inspector and geotechnical engineer. The shoring design engineer shall be notified of any unusual conditions encountered during installation. 4. Calibration data for each test jack, pressure gauge and master pressure gauge shall be verified by the special inspector and geotechnical engineer. The calibration tests shall be performed by an independent testing laboratory and within 120 calendar days of the data submitted. 5. Monitoring points shall be established at the top and at the anchor heads of selected soldier piles and at intermediate intervals as considered appropriate by the geotechnical engineer. 6. Control points shall be established outside the area of influence of the shoring system to ensure the accuracy of the monitoring readings. 7. The periodic basis of shoring monitoring, as a minimum, shall be as follows: a. Initial monitoring shall be performed prior to any excavation. b. Once excavation has begun, the periodic readings shall be taken weekly until excavation reaches the estimated subgrade elevation and the permanent foundation is complete. c. If performance of the shoring is within established guidelines, shoring design engineer may permit the periodic readings to be bi-weekly. Once initiated, bi-weekly readings shall continue until the building slab at ground floor level is completed and capable of transmitting lateral loads to the permanent structure. Thereafter, readings can be monthly. d. Where the building has been designed to resist lateral earth pressures, the periodic monitoring of the soldier piles and adjacent structure can be discontinued once the ground floor diaphragm and subterranean portion of the structure is capable of resisting lateral soil loads and approved by the shoring design engineer, geotechnical engineer and building official.

e. Additional readings shall be taken when requested by the special inspector, shoring design engineer, geotechnical engi- neer or building official. 8. Monitoring reading shall be submitted to the shoring design engineer, engineer in responsible charge and building official within three working days after they are conducted. Monitoring readings shall be accurate to within 0.01 feet. Results are to be submitted in tabular form showing at least the initial date of monitoring and reading, current monitoring date and reading and difference between the two readings. 9. If the total cumulative horizontal or vertical movement (from start of construction) of the existing buildings reaches [1] / 2 inch or soldier piles reaches 1 inch all excavation activities shall be suspended. The geotechnical and shoring design engineer shall determine the cause of movement, if any, and recommend corrective measures, if necessary, before excavation continues. 10. If the total cumulative horizontal or vertical movement (from start of construction) of the existing buildings reaches [3] / 4 inch or soldier piles reaches 1 [1] / 2 _inches all excavation activities shall be suspended until the causes, if any, can be determined.
CBC § 8.4 High relevance — show source text
15. If a tie-back anchor initially fails the testing requirements, the anchor shall be permitted to be regrouted and retested. If anchor continues to fail, the followings steps shall be taken: a. The contractor shall determine the cause of failure—variations of the soil conditions, installation methods, materials,

etc.

b. The contractor shall propose a solution to remedy the problem. The proposed solution will need to be reviewed and approved by the geotechnical engineer, shoring design engineer and building official. 16. After a satisfactory test, each anchor shall be locked-off in accordance with Section 8.4 of PTI Recommendations for Prestressed Rock and Soil Anchors.

1812A.6 Inspection, survey monitoring and observation. 1. The shoring design engineer or his designee shall make periodic visits to the job site for the purpose of observing the installa- tion of shoring system, testing of tie-back anchors and monitoring of survey. 2. Testing, inspection and observation shall be in accordance with testing, inspection and observation requirements approved by the building official. The following activities and materials shall be tested, inspected or observed by the special inspector and geotechnical engineer: a. Sampling and testing of concrete in soldier pile and tie-back anchor shafts. b. Fabrication of tie-back anchor pockets on soldier beams c. Installation and testing of tie-back anchors. d. Survey monitoring of soldier pile and tie-back load cells. e. Survey monitoring of existing buildings.

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3. A complete and accurate record of all soldier pile locations, depths, concrete strengths, tie-back locations and lengths, tie-back grout strength, quantity of concrete per pile, quantity of grout per tie-back and applied tie-back loads shall be maintained by the special inspector and geotechnical engineer. The shoring design engineer shall be notified of any unusual conditions encountered during installation. 4. Calibration data for each test jack, pressure gauge and master pressure gauge shall be verified by the special inspector and geotechnical engineer. The calibration tests shall be performed by an independent testing laboratory and within 120 calendar days of the data submitted. 5. Monitoring points shall be established at the top and at the anchor heads of selected soldier piles and at intermediate intervals as considered appropriate by the geotechnical engineer. 6. Control points shall be established outside the area of influence of the shoring system to ensure the accuracy of the monitoring readings. 7. The periodic basis of shoring monitoring, as a minimum, shall be as follows: a. Initial monitoring shall be performed prior to any excavation. b. Once excavation has begun, the periodic readings shall be taken weekly until excavation reaches the estimated subgrade elevation and the permanent foundation is complete. c. If performance of the shoring is within established guidelines, shoring design engineer may permit the periodic readings to be bi-weekly. Once initiated, bi-weekly readings shall continue until the building slab at ground floor level is _completed and capable of transmitting lateral loads to the permanent structure.
CBC § 18-33 High relevance — show source text
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Excavation for lagging shall not be started until concrete has achieved sufficient strength for all anticipated loads as deter- mined by the shoring design engineer. 9. Where boulders and/or cobbles have been identified in the geotechnical reports, the contractor shall be prepared to address boulders and/or cobbles that may be encountered during the drilling of soldier piles and tie-back anchors. 10. The grouting equipment shall produce grout free of lumps and indispensed cement. The grouting equipment shall be sized to enable the grout to be pumped in continuous operation. The mixer shall be capable of continuously agitating the grout. 11. The quantity of grout and grout pressure shall be recorded. The grout pressure shall be controlled to prevent excessive heave in soils or fracturing rock formations. 12. If post-grouting is required, post-grouting operation shall be performed after initial grout has set for 24 hours in the bond length only. Tie-backs shall be grouted over a sufficient length (anchor bond length) to transfer the maximum anchor force to the anchor grout. 13. Testing of anchors may be performed after post-grouting operations, provided that grout has reached a strength of 3,000 psi as required by PTI Recommendations for Prestressed Rock and Soil Anchors Section 6.11. 14. Anchor rods shall be tensioned straight and true. Excavation directly below the anchors shall not continue before those anchors are tested.

1812.6 Inspection, survey monitoring and observation. 1. The shoring design engineer or his designee shall make periodic inspections of the job site for the purpose of observing the installation of the shoring system, testing of tie-back anchors and monitoring of the survey. 2. Testing, inspection and observation shall be in accordance with testing, inspection and observation requirements approved by the building official. The following activities and materials shall be tested, inspected or observed by the special inspector and geotechnical engineer: a. Sampling and testing of concrete in soldier pile and tie-back anchor shafts. b. Fabrication of tie-back anchor pockets on soldier beams c. Installation and testing of tie-back anchors. d. Survey monitoring of soldier pile and tie-back load cells. e. Survey monitoring of existing buildings. 3. A complete and accurate record of all soldier pile locations, depths, concrete strengths, tie-back locations and lengths, tie-back grout strength, quantity of concrete per pile, quantity of grout per tie-back and applied tie-back loads shall be maintained by the special inspector and geotechnical engineer. The shoring design engineer shall be notified of any unusual conditions encountered during installation. 4. Calibration data for each test jack, pressure gauge and master pressure gauge shall be verified by the special inspector and geotechnical engineer. The calibration tests shall be performed by an independent testing laboratory and within 120 calendar days of the data submitted. 5. Monitoring points shall be established at the top and at the anchor heads of selected soldier piles and at intermediate intervals as considered appropriate by the geotechnical engineer. 6. Control points shall be established outside the area of influence of the shoring system to ensure the accuracy of the monitoring readings. 7. _The periodic basis of shoring monitoring, at a minimum,
CBC § 1812A.4.1 High relevance — show source text
Shafts shall be filled with concrete up to the elevation shown on the construction documents. The remainder of the shaft_ shall be permitted to be filled with controlled low-strength material (CLSM) when permitted by the construction documents. Excavation for lagging shall not be started until concrete has achieved sufficient strength for all anticipated loads as deter- mined by the shoring design engineer. 9. Where boulders and/or cobbles have been identified in the geotechnical reports, contractor shall be prepared to address boul- ders and/or cobbles that may be encountered during the drilling of soldier piles and tie-back anchors. 10. The grouting equipment shall produce grout free of lumps and indispensed cement. The grouting equipment shall be sized to enable the grout to be pumped in continuous operation. The mixer shall be capable of continuously agitating the grout. 11. The quantity of grout and grout pressure shall be recorded. The grout pressure shall be controlled to prevent excessive heave in soils or fracturing rock formations. 12. If post-grouting is required, post-grouting operation shall be performed after initial grout has set for 24 hours in the bond length only. Tie-backs shall be grouted over a sufficient length (anchor bond length) to transfer the maximum anchor force to the anchor grout. 13. Testing of anchors in accordance with Section 1812A.4.1, Item 7 may be performed after post-grouting operations, provided grout has reached strength of 3,000 psi as required by PTI Recommendations for Prestressed Rock and Soil Anchors Section 6.11.

14. Anchor rods shall be tensioned straight and true. Excavation directly below the anchors shall not continue before those anchors are tested.

15. If a tie-back anchor initially fails the testing requirements, the anchor shall be permitted to be regrouted and retested. If anchor continues to fail, the followings steps shall be taken: a. The contractor shall determine the cause of failure—variations of the soil conditions, installation methods, materials,

etc.

b. The contractor shall propose a solution to remedy the problem. The proposed solution will need to be reviewed and approved by the geotechnical engineer, shoring design engineer and building official. 16. After a satisfactory test, each anchor shall be locked-off in accordance with Section 8.4 of PTI Recommendations for Prestressed Rock and Soil Anchors.

1812A.6 Inspection, survey monitoring and observation. 1. The shoring design engineer or his designee shall make periodic visits to the job site for the purpose of observing the installa- tion of shoring system, testing of tie-back anchors and monitoring of survey. 2. Testing, inspection and observation shall be in accordance with testing, inspection and observation requirements approved by the building official. The following activities and materials shall be tested, inspected or observed by the special inspector and geotechnical engineer: a. Sampling and testing of concrete in soldier pile and tie-back anchor shafts. b. Fabrication of tie-back anchor pockets on soldier beams c. Installation and testing of tie-back anchors. d. Survey monitoring of soldier pile and tie-back load cells. e. Survey monitoring of existing buildings.

2025 CALIFORNIA BUILDING CODE 18A-27

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CBC § 1705.8 High relevance — show source text

TABLE 1705.8—REQUIRED SPECIAL INSPECTIONS AND TESTS OF CAST-IN-PLACE DEEP FOUNDATION ELEMENTS	Col2	Col3
TYPE	CONTINUOUS SPECIAL INSPECTION	PERIODIC SPECIAL INSPECTION
1. Inspect drilling operations and maintain complete and accurate records for each element.	X	—
2. Verify placement locations and plumbness, confirm element diameters, bell diameters (if applicable), lengths, embedment into bedrock (if applicable) and adequate end-bearing strata capacity. Record concrete or grout volumes.	X	—
3. For concrete elements, perform tests and additional special inspections in accordance with Section 1705.3.	In accordance with Section 1705.3	In accordance with Section 1705.3

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SPECIAL INSPECTIONS AND TESTS

geotechnical report and the construction documents prepared by the registered design professional shall be used to determine compliance.

1705.10 Structural integrity of deep foundation elements. Whenever there is a reasonable doubt as to the structural integrity of a deep foundation element, an engineering assessment shall be required. The engineering assessment shall include tests for defects performed in accordance with ASTM D4945, ASTM D5882, ASTM D6760 or ASTM D7949, or other approved method.

1705.11 Fabricated items. Special inspections of fabricated items shall be performed in accordance with Section 1704.2.5.

1705.12 Special inspections for wind resistance. Special inspections for wind resistance specified in Sections 1705.12.1 through 1705.12.3, unless exempted by the exceptions to Section 1704.2, are required for buildings and structures constructed in the following areas:

In wind Exposure Category B, where basic wind speed, V, is 150 mph (67 m/sec) or greater.
In wind Exposure Category C or D, where basic wind speed, V, is 140 mph (62.6 m/sec) or greater.

1705.12.1 Structural wood. Continuous special inspection is required during field gluing operations of elements of the main windforce-resisting system. Periodic special inspection is required for nailing, bolting, anchoring and other fastening of elements of the main windforce-resisting system, including wood shear walls, wood diaphragms, drag struts, braces and hold-downs.

Exception: Special inspections are not required for wood shear walls, shear panels and diaphragms, including nailing, bolting, anchoring and other fastening to other elements of the main windforce-resisting system, where the lateral resistance is provided by structural sheathing and the specified fastener spacing at panel edges is more than 4 inches (102 mm) on center.

CBC § 1705A.8 Medium relevance — show source text

TABLE 1705A.8—REQUIRED SPECIAL INSPECTIONS AND TESTS OF CAST-IN-PLACE DEEP FOUNDATION ELEMENTS	Col2	Col3
TYPE	CONTINUOUS SPECIAL INSPECTION	PERIODIC SPECIAL INSPECTION
1. Inspect drilling operations and maintain complete and accurate records for each element.	X	—
2. Verify placement locations and plumbness, confirm element diameters, bell diameters (if applicable), lengths, embedment into bedrock (if applicable) and adequate end-bearing strata capacity. Record concrete or grout volumes.	X	—
3. For concrete elements, perform tests and additional special inspections in accordance with Section 1705_A_.3.	In accordance with Section 1705_A_.3	In accordance with Section 1705_A_.3

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1705A.8.1 Micropile tests. Micropile preproduction and production load tests shall be in accordance with Section 1810A.3.10.4.

1705A.9.1 Helical pile tests. Helical pile preproduction and production load tests shall be in accordance with Section 1810A.3.1.5.1.

1705 A .10 Structural integrity of deep foundation elements. Whenever there is a reasonable doubt as to the structural integrity of a deep foundation element, an engineering assessment shall be required. The engineering assessment shall include tests for defects performed in accordance with ASTM D4945, ASTM D5882, ASTM D6760 or ASTM D7949, or other approved method.

1705 A .11 Fabricated items. Special inspections of fabricated items shall be performed in accordance with Section 1704 A .2.5.

1705 A .12 Special inspections for wind resistance. Special inspections for wind resistance specified in Sections 1705 A .12.1 through 1705 A .12.3, unless exempted by the exceptions to Section 1704 A .2, are required for buildings and structures constructed in the following areas:

In wind Exposure Category B, where basic wind speed, V, is 150 mph (67 m/sec) or greater.
In wind Exposure Category C or D, where basic wind speed, V, is 140 mph (62.6 m/sec) or greater.

1705 A .12.1 Structural wood. Continuous special inspection is required during field gluing operations of elements of the main windforce-resisting system. Periodic special inspection is required for nailing, bolting, anchoring and other fastening of elements of the main windforce-resisting system, including wood shear walls, wood diaphragms, drag struts, braces and hold-downs.

CBC § 1705.6 Medium relevance — show source text

Exception: Where Section 1803 does not require reporting of materials and procedures for fill placement, the special inspector shall verify that the in-place dry density of the compacted fill is not less than 90 percent of the maximum dry density at optimum moisture content determined in accordance with ASTM D1557.

TABLE 1705.6—REQUIRED SPECIAL INSPECTIONS AND TESTS OF SOILS	Col2	Col3
TYPE	CONTINUOUS SPECIAL INSPECTION	PERIODIC SPECIAL INSPECTION
1. Verify materials below shallow foundations are adequate to achieve the design bearing capacity.	—	X
2. Verify excavations are extended to proper depth and have reached proper material.	—	X
3. Perform classification and testing of compacted fill materials.	—	X
4. During fill placement, verify use of proper materials and procedures in accordance with the provi- sions of the approved geotechnical report. Verify densities and lift thicknesses during placement and compaction of compacted fill.	X	—
5. Prior to placement of compacted fill, inspect subgrade and verify that site has been prepared properly.	—	X

17-12 2025 CALIFORNIA BUILDING CODE

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

SPECIAL INSPECTIONS AND TESTS

1705.6.1 Soil fill. [OSHPD 1R, 2 & 5] All fills used to support the foundations of any building or structure shall be continuously inspected by the geotechnical engineer or his or her qualified representative. It shall be the responsibility of the geotechnical engi- neer to verify that fills meet the requirements of the approved construction documents and to coordinate all fill inspection and testing during construction involving such fills.

TABLE 1705.7—REQUIRED SPECIAL INSPECTIONS AND TESTS OF DRIVEN DEEP FOUNDATION ELEMENTS	Col2	Col3
TYPE	CONTINUOUS SPECIAL INSPECTION	PERIODIC SPECIAL INSPECTION
1.

Frequently asked questions

Who counts as a "qualified representative of the geotechnical engineer"?

The CBC text requires a qualified representative of the geotechnical engineer but does not define the term in these sections; qualification is understood to mean someone authorized and experienced under the geotechnical engineer of record to perform continuous observation. Local enforcement may clarify required credentials. § 1705.7.1.

Does "continuous" mean the geotechnical rep must be physically present 24/7?

The code requires continuous observation during the installation of driven piles but does not specify a numeric time definition for "continuous" in the sections retrieved. In practice this means the representative must be present for the entire pile‑driving operation; local building officials may impose further interpretation. § 1705.7.1.

If a dynamic formula is used, what specific dynamic data must be reported?

When allowable pile loads are determined by a dynamic load formula, the representative must report the design formula used and the permanent penetration under the last 10 blows, along with other driving records. § 1705.7.1.

Can a structural special inspector satisfy the requirement?

No — driven piles must be continuously observed by a qualified representative of the geotechnical engineer (not merely the structural special inspector), per § 1705.7.1; ensure the geotechnical engineer of record assigns a qualified observer.

Are helical and cast‑in‑place piles handled the same way?

No — the CBC includes separate continuous‑inspection rules and recording requirements for helical piles (§ 1705.9/1705A.9) and cast‑in‑place deep foundations (§ 1705.8/1705A.8). Check the applicable table and section for the element type.

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What special inspections/tests are required for deep foundations (driven, cast-in-place, helical)?

How is the structural integrity of deep foundation elements verified when defects are suspected?

What special inspections apply to soil improvement, shoring and vibro stone columns?

Foundations & Soils — Required Inspections and Testing

California Building Code

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