Every contract for the construction of public work made by the mayor shall contain such stipulations as shall require the contractor to erect and maintain good and sufficient guards, barricades and signals at all unsafe places at or near where the work or improvement contemplated by the contractor is to be done or made; also such stipulations as will render the contractor and the contractor's bondspersons in every case liable to the city for any liability that it may incur for any injury that any person may suffer by reason of the failure to erect and maintain such good and sufficient barricades, guards or signals; every contract shall also contain a provision that in case any injury to any person shall arise by reason of the failure to erect and maintain such barricades, guards and signals or by reason of negligence of the contractor, the contractor's agents or employees during the performance of the contract or before the warrants to become due on the contract shall have been delivered, the city and its officials may withhold such payment so long as shall seem necessary for the indemnity of the city. Such contracts shall also contain a provision that when the contractor shall remove any earth from any street, alley or other public place, the same shall, when replaced, be solidly tamped and shall make such further rules and regulations in the city's behalf as will ensure full protection to the city from loss or liability, and make such further stipulations in such contracts as will ensure the city from all loss or liability that ray arise by reason of the carelessness and all negligence of such contractors, their agents or servants. (Prior code § 13-1-1)