# US 5,707,181 A · Method of producing an intended breaking point in a tension member for a soil anchor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,707,181 A - Document ID: US5707181A - Status: Granted - Kind: A - Application number: 08/582,452 - Filed: 1996-01-03 - Granted: 1998-01-13 - Earliest claimed: 1995-01-04 - Assignees: Dyckerhoff & Widmann Aktiengesellschaft - Inventors: Hans-Peter von Allmen; Reinhard Klockner; Erich Richartz - Web page: https://patentgrep.com/patent/US5707181A ## CPC - C21D 1/42: Induction heating - C21D 9/0068: {for particular articles not mentioned below} - E02D 5/54: Piles with prefabricated supports or anchoring parts; Anchoring piles {(E02D5/44 takes precedence; ground anchors E02D5/80; anchored foundations E02D27/50)} - E02D 5/80: Ground anchors {(for galleries, tunnels or shafts E21D21/00)} - C21D 2221/00: Treating localised areas of an article - Y02P 10/25: Process efficiency - Y10T 225/12: With preliminary weakening - Y10T 225/325: With means to apply moment of force to weakened work - C21D: MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING (surface treatment of metallic material involving at least one process provided for in class C23 and at least one process covered by this subclass C23F17/00; unidirectional solidification of eutectic materials or unidirectional demixing of eutectoid materials C30B) - E02D: FOUNDATIONS; EXCAVATIONS; EMBANKMENTS (specially adapted for hydraulic engineering E02B); UNDERGROUND OR UNDERWATER STRUCTURES {(tunnels, tunnelling, mining E21)} - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A method of producing an intended breaking point at a predetermined location of a tension member for a soil anchor of a strain-hardened steel or a steel which is not which is not in a thermodynamic equilibrium, for example, a wire or a steel wire strand, to enable removal of the free steel length after use by applying a tensile force which exceeds the working load. The predetermined breaking point is obtained by heating the tension member at a predetermined location in a controlled manner to a temperature at which the state of strain-hardening or the state of being not in a thermodynamic equilibrium is at least partially cancelled, wherein the predetermined breaking point has a breaking load which is equal to or smaller than the breaking load of the untreated tension member, but greater than the yield point of the untreated tension member. ## Claims ### Claim 1 A method of producing a predetermined breaking point at a predetermined location of a tension member of a soil anchor composed of a steel in the strain-hardened state, for enabling removal of a free steel length after use of the soil anchor by applying a tensile force which exceeds a working load, the method comprising, prior to mounting of the tension member, subjecting the tension member at the predetermined location to controlled heating to a temperature at which the strain-hardened state is at least partially cancelled. ### Claim 2 (depends on 1) The method according to claim 1, comprising heating the tension member to a temperature of between 200.degree. and 800.degree. C. ### Claim 3 (depends on 2) The method according to claim 2, comprising heating the tension member to a temperature of between 200.degree. and 600.degree. C. ### Claim 4 (depends on 1) The method according to claim 1, comprising carrying out heating by induction. ### Claim 5 (depends on 4) The method according to claim 4, comprising producing induction by at least one coil surrounding the tension member. ### Claim 6 (depends on 1) The method according to claim 1, comprising heating by means of a flame. ### Claim 7 (depends on 1) The method according to claim 1, comprising heating by means of a hot gas jet. ### Claim 8 (depends on 1) The method according to claim 1, comprising heating by immersion in a hot liquid. ### Claim 9 (depends on 1) The method according to claim 1, comprising heating by carrying out an exothermic chemical reaction. ### Claim 10 A method of producing a predetermined breaking point at a predetermined location of a tension member of a soil anchor composed of a steel in the state of not being in a thermodynamic equilibrium, for enabling removal of a free steel length after use of the soil anchor by applying a tensile force which exceeds a working load, the method comprising, prior to mounting of the tension member, subjecting the tension member at the predetermined location to controlled heating to a temperature at which the state of not being in a thermodynamic equilibrium is at least partially cancelled. ### Claim 11 (depends on 10) The method according to claim 10, comprising heating the tension member to a temperature of between 200.degree. and 800.degree. C. ### Claim 12 (depends on 10) The method according to claim 10, comprising heating the tension member to a temperature of between 600.degree. and 800.degree. C. ### Claim 13 (depends on 10) The method according to claim 10, comprising carrying out heating by induction. ### Claim 14 (depends on 10) The method according to claim 10, comprising producing induction by at least one coil surrounding the tension member. ### Claim 15 (depends on 10) The method according to claim 10, comprising heating by means of a flame. ### Claim 16 (depends on 10) The method according to claim 10, comprising heating by means of a hot gas jet. ### Claim 17 (depends on 10) The method according to claim 10, comprising heating by immersion in a hot liquid. ### Claim 18 (depends on 10) The method according to claim 10, comprising heating by carrying out an exothermic chemical reaction. ### Claim 19 A tension member for a soil anchor of a steel in a strain-hardened state or a state of being not in a thermodynamic equilibrium, the tension member comprising a predetermined breaking point for enabling removal of a free steel length of the tension member after use by applying a tensile force exceeding a working load, the predetermined breaking point obtained by heating the tension member at a predetermined location in a controlled manner to a temperature at which the state of strain-hardening or the state of being not in a thermodynamic equilibrium is at least partially cancelled, wherein the predetermined breaking point has a breaking load which is equal to or smaller than the breaking load of the untreated tension member, but greater than the yield point of the untreated tension member.