5_Vol3_d4.3_Section 5 Earth and pipe works_en_GIR_rev6.docx  5.4.6.9 Reinforcement  Unless otherwise dictated by the design, cast in situ piles shall be reinforced over the whole of their  length. The minimum longitudinal reinforcement shall be 1.0% of the gross concrete area in the top  3m of the pile and 0.8% of the gross concrete area in the remainder of the pile. Lateral ties shall be  If the pile is to be subjected to further driving the additional length shall be of an approved grade of  concrete. Piles shall not be driven until the added concrete has reached the specified characteristic  strength of the concrete of the pile.  For lap or splice joints sufficient link bars shall be provided to resist eccentric forces.  Welded joints shall be made in accordance with DIN 1910 and before welding the main longitudinal  reinforcing bars in the head of the pile shall be exposed for at least 300 mm below the position of the  weld.  In preparation for lengthening a normal reinforced pile the concrete shall be cut off square to expose a  sufficient length to ensure that the full strength of the bars will be developed across the joint.  If the pile has been completely driven but the sound concrete is below cut-off level the pile shall be  made good to cut-off level with concrete of a class not inferior to that of the concrete of the pile. If the pile is to be subjected to further driving the head shall be replaced with concrete of an approved  class.  In preparation for repairing the head of a pile the concrete shall be cut off square at sound concrete to  expose the reinforcement and all loose particles shall be removed by wire brushing followed by wash- ing with water.  5.4.6.8 Repair and lengthening of piles  Driving stresses may be estimated by performing wave equation analyses or by dynamic monitoring of  force and acceleration at the pile head during pile driving.   0.85 f'c  (compression)   0.7 fy of steel reinforcement (tension)  For concrete piles, driving stresses shall be checked and shall not exceed the following values:  If there has been a delay in pile driving operations for one hour or longer, the refusal criteria stated  above shall not apply until the pile has been advanced at least 0.3meter following the resumption of  pile driving. However, in no case shall the blow count exceed 800 blows for 152 mm of penetrations. Detail criteria is given in API 2A-WSD (2000) clause 12.5.6, for steel driving piles  Pile driving shall be refused at the point where driving resistance exceeds either 300 blows per 0.3 me- ter (roughly 1 mm per blow) for five consecutive 0.3 meters (1.5 meters); or 800 blows for 0.3 meter  of penetration. Jetting may be carried out only when approved by the Engineer and the Contractor shall submit de- tailed proposals and it shall not normally be undertaken over the last 3 m of penetration.  Where preboring is required by the Contractor each pile shall be pitched into a hole pre-bored before  driving to the required depth.  Where piles have risen or moved out of plumb as a result of driving adjacent piles the Contractor shall  submit to the Engineer his proposals for correcting such faults and their avoidance in subsequent work.  Measurements shall be taken to determine the movement of ground or any pile resulting from the driv- ing process when required by the Engineer.  38 of 49 Construction of Giresun Wastewater Treatment Plant  Tender Dossier Volume 3 Employer’s Requirements  Section 05: Earth Works, Pipe Works and Ground Improvement 