A method for judging the safety status of foundation pit

Abstract

The present invention belongs to the field of building construction technology, and particularly relates to a method for judging the safety status of a foundation pit. It includes assuming that the foundation pit is a first-level foundation pit, and all alarm values ​​are taken as the first-level foundation pit alarm level. Starting from the inclination alarm in the monitoring data, the safety status of the foundation pit is jointly judged in combination with multiple monitoring data and construction conditions. After the inclination alarm, the judgment is made according to the two lines of single-day rate alarm and cumulative data alarm respectively; taking inclination measurement, a relatively important monitoring indicator in the foundation pit construction process, as the starting point, a comprehensive judgment is made in combination with other monitoring data and construction conditions in the foundation pit construction, to improve the foundation pit risk determination and control measures process, improve the efficiency of construction safety risk management, discover problems in advance, and solve safety hazards.

Description

Technical Field

[0001] The invention belongs to the technical field of building construction, and in particular relates to a method for judging the safety status of a foundation pit. Background Art

[0002] At present, the height and depth of buildings are constantly expanding in the development of buildings, and the requirements for underground space are getting higher and higher. However, due to technical and management reasons, some accidents may occur during the construction of foundation pits, causing adverse effects. In order to better solve the potential safety hazards in the construction of foundation pits, it is necessary to use systematic and process-based safety management and control to propose control measures. Especially in the construction of deep foundation pits, the evaluation of the safety status of foundation pits is of great significance to the construction of foundation pits. Generally, data is obtained through various monitoring technologies, and managers judge the safety of foundation pits through data. However, this judgment method has the following problems:

[0003] (1) During the data review process, the data is a single situation and is not combined with a comprehensive analysis of multiple situations. Single data is often one-sided and requires comprehensive judgment; (2) The level of management personnel is uneven, and only the data report cannot determine whether the foundation pit is safe; (3) Experienced managers have their own experience in foundation pit safety evaluation, but this experience has not been quantified into indicators.

[0004] In view of this, it is necessary to study a method to judge the safety status of the foundation pit to ensure the safety of construction. Summary of the invention

[0005] The present invention provides a method for judging the safety status of a foundation pit, which mainly uses inclinometer, an important monitoring indicator in the foundation pit construction process, as a starting point, and combines other monitoring data and construction conditions in the foundation pit construction to make a comprehensive judgment, improve the foundation pit risk determination and control measures process, improve the efficiency of construction safety risk management, discover problems in advance, and solve safety hazards.

[0006] In order to solve the above technical problems, the present invention includes the following technical solutions:

[0007] A method for judging the safety status of a foundation pit, comprising:

[0008] Assuming that the foundation pit is a first-level foundation pit, all alarm values ​​are taken from the first-level foundation pit alarm level. Starting from the inclination alarm in the monitoring data, the safety status of the foundation pit is jointly judged in combination with multiple monitoring data and construction conditions. After the inclination alarm, the judgment is made according to the single-day rate alarm and the cumulative data alarm. Among them,

[0009] Single-day rate alarm:

[0010] If A t ≥±3mm, make a comprehensive judgment:

[0011] The first step is to make a judgment based on the situation of the adjacent inclination measurement. If there is no alarm in the adjacent inclination measurement, then check whether the displacement of the surrounding retaining wall top is an alarm. If W≤3mm and there is no alarm in the displacement of the retaining wall top, then start monitoring the next day. If there is no alarm and A t ≤±3mm, the single-day rate alarm event ends and subsequent attention is strengthened; if the monitoring alarm is on the next day and A t ≥±3mm, perform the intensified monitoring on the day; if the adjacent inclination alarm and A j ≥±3mm, perform the daily intensive monitoring;

[0012] The second step is to make further judgments based on whether the encrypted monitoring has an alarm. If the encrypted monitoring has not an alarm and A t ≤±3mm, the next day retest phase will begin; if the next day retest also does not alarm and A t ≤±3mm, the single-day rate alarm event of the inclinometer ends; if the alarm still occurs when the next day is repeated and A t ≥±3mm, then proceed to the next step of in-depth judgment; if the day's intensive monitoring alarm and A t ≥±3mm, then proceed to the next step of in-depth judgment;

[0013] The third step is to conduct a comprehensive analysis of the actual working conditions of the foundation pit, considering four factors: whether there is a pile load on the edge of the foundation pit, whether the over-excavation / slope meets the requirements, whether the precipitation meets the requirements, and whether the support exposure time is too long;

[0014] Step 4: Retest on the third day. If there is no alarm after retest on the third day and A t ≤±3mm, the event is archived. If the alarm still occurs after retesting on the third day and A t ≥±3mm, the owner, general contractor, designer, construction participants, supervisor, and monitoring party will hold a meeting to decide on a solution and finally file the incident;

[0015] Accumulated data alarm:

[0016] Based on the safety value limit value assigned by the design, comprehensive judgment is made:

[0017] Step 1: Check whether the accumulated data of the previous three days is an alarm. If no alarm is given and A L ≤±0.4%H, it is within the safety limit, otherwise it will proceed to the next judgment;

[0018] Step 2: If the single rate alarm is not triggered and A t ≤±3mm, the safety value limit value assigned by the design is considered to be small. When the cumulative data alarm value exceeds 1.5 times the design cumulative alarm value, the owner, general contractor, designer, construction participant, supervisor, and monitoring party shall be organized to hold a meeting to make a decision. Otherwise, proceed to the next judgment;

[0019] Step 3: Combine the situation of the adjacent inclination measurement to make a judgment. If the adjacent inclination measurement does not alarm and A j ≤±3mm, then combine the surrounding retaining wall top displacement to see if an alarm is issued. If there is no alarm for the surrounding wall top displacement and W≤3mm, the inclinometer will enter the next day's monitoring. If there is no alarm for the next day's monitoring and A t ≤±3mm, the single-day rate alarm event ends and subsequent attention is strengthened; if the monitoring alarm is on the next day and A t ≥±3mm, the monitoring will be intensified on that day; if there is an alarm in the adjacent inclination measurement and A j ≥±3mm, perform the daily intensive monitoring;

[0020] Step 4: Further judge whether the encrypted monitoring alarms. If the encrypted monitoring does not alarm on the day and A j ≤±3mm, the next day will be the next day. If there is no alarm during the next day, and A j ≤±3mm, the single-day rate alarm event ends. If the alarm still occurs when the test is repeated the next day and A t ≥±3mm, then proceed to the next step of in-depth judgment; if the day's intensive monitoring alarm and A t ≥±3mm, then proceed to the next step of in-depth judgment;

[0021] Step 5: Conduct a comprehensive analysis of the actual working conditions of the foundation pit, considering four factors: whether there is a pile load on the edge of the foundation pit, whether the over-excavation / slope meets the requirements, whether the precipitation meets the requirements, and whether the support exposure time is too long;

[0022] Step 6: Retest on the third day. If there is no alarm after retest on the third day and A t ≤±3mm, the event is archived. If the alarm still occurs after retesting on the third day and A t ≥±3mm, the owner, general contractor, designer, construction participants, supervisor, and monitoring party will hold a meeting to decide on a solution and finally file the incident;

[0023] The single-day inclinometer data is A t , the accumulated inclinometric data is A L , the adjacent inclinometric data is A j , the displacement of the top of the retaining wall is W, and the unit is mm.

[0024] Furthermore, it also includes: when there is no pile loading on the side of the foundation pit, the management personnel will be reminded to issue a warning prohibiting the pile loading on the side of the foundation pit after inspecting the site; if there is pile loading on the side of the foundation pit, it is prohibited to pile soil or materials within 1 meter around the construction pit according to the specifications; to prevent pit wall landslides, according to the soil conditions and the depth of the pit or trench, abandoned soil shall not be piled within a certain distance on both sides of the pit top; and according to the requirements of the specifications, it is judged whether the pile loading distance meets the requirements. If not, the pile loading will be immediately required to be handled. If it is within the requirements of the specifications, it is recommended to remove or expand the pile loading distance.

[0025] Furthermore, it also includes: if there is no over-excavation or the slope does not meet the requirements, the management personnel are reminded to pay attention to the potential hidden dangers caused by over-excavation; if there is over-excavation or the slope does not meet the requirements, the next step of judgment is entered. If it is in the support formation stage, the steel bar binding is accelerated and concrete is poured to form a corner brace; if it is only in the excavation stage, the construction is suspended. Depending on the situation, whether to proceed to the next step of work, backfilling of earthwork or detailed zoning and block excavation can be carried out.

[0026] Furthermore, it also includes: if H water level < H excavation surface, the precipitation meets the requirement; otherwise, the precipitation well is started to carry out precipitation until the precipitation requirement is met.

[0027] Furthermore, it also includes: if the steel bar binding and concrete pouring are both within the specified time, then pay more attention to the support situation in the future; if the support construction exceeds the specified time, resulting in the support exposure time being too long, it is handled in stages: if it is in the steel bar binding stage, then accelerate the formation of the foundation pit edge support, pour concrete, and add an appropriate amount of fast-setting additives; if it is in the concrete pouring stage, pour concrete, and add an appropriate amount of fast-setting additives.

[0028] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0029] The method for judging the safety status of a foundation pit of the present invention takes inclinometer, a relatively important monitoring indicator in the foundation pit construction process, as a starting point, and makes a comprehensive judgment in combination with other monitoring data and construction conditions in the foundation pit construction, improves the foundation pit risk determination and control measures process, improves the efficiency of construction safety risk management, discovers problems in advance, and solves safety hazards. The method is highly targeted, scientific and reliable, simple to operate, and low in cost, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The present invention is a flowchart of a method for determining the safety status of a foundation pit in one embodiment of the present invention. DETAILED DESCRIPTION

[0031] The following is a further detailed description of a method for determining the safety status of a foundation pit provided by the present invention in conjunction with the accompanying drawings and specific embodiments. According to the following description, the advantages and features of the present invention will become clearer. It should be noted that the accompanying drawings are all in a very simplified form and use non-precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. For the convenience of description, the "upper" and "lower" described below are consistent with the upper and lower directions of the accompanying drawings, but this cannot be a limitation of the technical solution of the present invention.

[0032] Embodiment 1

[0033] like Figure 1As shown, the present invention provides a method for determining the safety status of a foundation pit, comprising:

[0034] Step S1, assuming that the foundation pit is a first-level foundation pit, all alarm values ​​are taken as the first-level foundation pit alarm level, starting from the inclination alarm in the monitoring data, combining multiple monitoring data and construction conditions to jointly judge the safety status of the foundation pit, and after the inclination alarm, judge according to the single-day rate alarm and cumulative data alarm.

[0035] Step S2, daily rate alarm:

[0036] If A t ≥±3mm, make a comprehensive judgment:

[0037] The first step is to make a judgment based on the situation of the adjacent inclination measurement. If there is no alarm in the adjacent inclination measurement, then check whether the displacement of the surrounding retaining wall top is an alarm. If W≤3mm and there is no alarm in the displacement of the retaining wall top, then start monitoring the next day. If there is no alarm and A t ≤±3mm, the single-day rate alarm event ends and subsequent attention is strengthened; if the monitoring alarm is on the next day and A t ≥±3mm, perform the intensified monitoring on the day; if the adjacent inclination alarm and A j ≥±3mm, perform the daily intensive monitoring;

[0038] The second step is to make further judgments based on whether the encrypted monitoring has an alarm. If the encrypted monitoring has not an alarm and A t ≤±3mm, the next day retest phase will begin; if the next day retest also does not alarm and A t ≤±3mm, the single-day rate alarm event of the inclinometer ends; if the alarm still occurs when the next day is repeated and A t ≥±3mm, then proceed to the next step of in-depth judgment; if the day's intensive monitoring alarm and A t ≥±3mm, then proceed to the next step of in-depth judgment;

[0039] The third step is to conduct a comprehensive analysis of the actual working conditions of the foundation pit, considering four factors: whether there is a pile load on the edge of the foundation pit, whether the over-excavation / slope meets the requirements, whether the precipitation meets the requirements, and whether the support exposure time is too long;

[0040] Step 4: Retest on the third day. If there is no alarm after retest on the third day and A t ≤±3mm, the event is archived. If the alarm still occurs after retesting on the third day and A t ≥±3mm, the owner, general contractor, designer, construction participants, supervisor, and monitoring party will hold a meeting to decide on a solution and finally file the incident;

[0041] Step S3, cumulative data alarm:

[0042] Based on the safety value limit value assigned by the design, comprehensive judgment is made:

[0043] Step 1: Check whether the accumulated data of the previous three days is an alarm. If no alarm is given and A L ≤±0.4%H, it is within the safety limit, otherwise it will proceed to the next judgment;

[0044] Step 2: If the single rate alarm is not triggered and A t ≤±3mm, the safety value limit value assigned by the design is considered to be small. When the cumulative data alarm value exceeds 1.5 times the design cumulative alarm value, the owner, general contractor, designer, construction participant, supervisor, and monitoring party shall be organized to hold a meeting to make a decision. Otherwise, proceed to the next judgment;

[0045] Step 3: Combine the situation of the adjacent inclination measurement to make a judgment. If the adjacent inclination measurement does not alarm and A j ≤±3mm, then combine the surrounding retaining wall top displacement to see if an alarm is issued. If there is no alarm for the surrounding wall top displacement and W≤3mm, the inclinometer will enter the next day's monitoring. If there is no alarm for the next day's monitoring and A t ≤±3mm, the single-day rate alarm event ends and subsequent attention is strengthened; if the monitoring alarm is on the next day and A t ≥±3mm, the monitoring will be intensified on that day; if there is an alarm in the adjacent inclination measurement and A j ≥±3mm, perform the daily intensive monitoring;

[0046] Step 4: Further judge whether the encrypted monitoring alarms. If the encrypted monitoring does not alarm on the day and A j ≤±3mm, the next day will be the next day. If there is no alarm during the next day, and A j ≤±3mm, the single-day rate alarm event ends. If the alarm still occurs when the test is repeated the next day and A t ≥±3mm, then proceed to the next step of in-depth judgment; if the day's intensive monitoring alarm and A t ≥±3mm, then proceed to the next step of in-depth judgment;

[0047] Step 5: Conduct a comprehensive analysis of the actual working conditions of the foundation pit, considering four factors: whether there is a pile load on the edge of the foundation pit, whether the over-excavation / slope meets the requirements, whether the precipitation meets the requirements, and whether the support exposure time is too long;

[0048] Step 6: Retest on the third day. If there is no alarm after retest on the third day and A t ≤±3mm, the event is archived. If the alarm still occurs after retesting on the third day and A t ≥±3mm, the owner, general contractor, designer, construction participants, supervisor, and monitoring party will hold a meeting to decide on a solution and finally file the incident;

[0049] The single-day inclinometer data is A t, the accumulated inclinometric data is A L , the adjacent inclinometric data is A j , the displacement of the top of the retaining wall is W, and the unit is mm.

[0050] like Figure 1 As shown, in one implementation of the present invention for determining the safety status of a foundation pit, the present invention further includes:

[0051] Step S4, if there is no heap pile at the edge of the foundation pit, the management personnel will be prompted to inspect the site and issue a warning prohibiting heap pile at the edge of the foundation pit. If there is heap pile at the edge of the foundation pit, it is prohibited to pile up soil or materials within 1 meter around the construction foundation pit according to the specifications; to prevent pit wall landslides, according to the soil conditions and the depth of the pit or trench, abandoned soil shall not be piled within a certain distance on both sides of the pit top; and according to the requirements of the specifications, it is judged whether the heap pile distance meets the requirements. If not, it is immediately required to deal with the heap pile. If it is within the requirements of the specifications, it is recommended to remove or expand the heap pile distance.

[0052] like Figure 1 As shown, in one implementation of the present invention for determining the safety status of a foundation pit, the present invention further includes:

[0053] Step S5, if there is no over-excavation or the slope meets the requirements, the management personnel are reminded to pay attention to the potential hidden dangers caused by over-excavation; if there is over-excavation or the slope does not meet the requirements, the next step of judgment is entered. If it is in the support formation stage, the steel bar binding is accelerated and concrete is poured to form a corner brace; if it is only in the excavation stage, the construction is suspended. Depending on the situation, whether to proceed to the next step of work, backfilling of earthwork can be carried out, or excavation in detailed areas and blocks can be carried out.

[0054] like Figure 1 As shown, in one implementation of the present invention for determining the safety status of a foundation pit, the present invention further includes:

[0055] Step S6: if H 水位 <H 开挖面 , the precipitation meets the requirements; otherwise, the precipitation well is started to carry out precipitation until the precipitation requirements are met.

[0056] like Figure 1 As shown, in one implementation of the present invention for determining the safety status of a foundation pit, the present invention further includes:

[0057] Step S7, if the steel bar binding and concrete pouring are both within the specified time, then pay more attention to the support situation in the future; if the support construction exceeds the specified time, resulting in the support exposure time being too long, it is handled in stages: if it is in the steel bar binding stage, accelerate the formation of the foundation pit edge support, pour concrete, and add an appropriate amount of fast-setting additives; if it is in the concrete pouring stage, pour concrete, and add an appropriate amount of fast-setting additives.

[0058] The above examples are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above examples. The above embodiments only express several embodiments of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for judging the safety status of a foundation pit, characterized in that: include: Assuming that the foundation pit is a first-level foundation pit, all alarm values ​​are taken from the first-level foundation pit alarm level. Starting from the inclination alarm in the monitoring data, the safety status of the foundation pit is jointly judged in combination with multiple monitoring data and construction conditions. After the inclination alarm, the judgment is made according to the single-day rate alarm and the cumulative data alarm. Among them, Single-day rate alarm: If A t ≥±3mm, make a comprehensive judgment: The first step is to make a judgment based on the situation of the adjacent inclination measurement. If there is no alarm in the adjacent inclination measurement, then check whether the displacement of the surrounding retaining wall top is an alarm. If W≤3mm and there is no alarm in the displacement of the retaining wall top, then start monitoring the next day. If there is no alarm and A t ≤±3mm, the single-day rate alarm event ends and subsequent attention is strengthened; if the monitoring alarm is on the next day and A t ≥±3mm, perform the intensified monitoring on the day; if the adjacent inclination alarm and A j ≥±3mm, perform the daily intensive monitoring; The second step is to make further judgments based on whether the encrypted monitoring has an alarm. If the encrypted monitoring has not an alarm and A t ≤±3mm, the next day retest phase will begin; if the next day retest also does not alarm and A t ≤±3mm, the single-day rate alarm event of the inclinometer ends; if the alarm still occurs when the next day is repeated and A t ≥±3mm, then proceed to the next step of in-depth judgment; if the day's intensive monitoring alarm and A t ≥±3mm, then proceed to the next step of in-depth judgment; The third step is to conduct a comprehensive analysis of the actual working conditions of the foundation pit, taking into account four factors: whether there is a pile load on the edge of the foundation pit, whether the over-excavation / slope meets the requirements, whether the precipitation meets the requirements, and whether the support exposure time is too long; if the steel bar binding and concrete pouring are both within the specified time, then pay more attention to the support situation in the future; if the support construction exceeds the specified time, resulting in a long exposure time of the support, it will be handled in stages: if it is in the steel bar binding stage, accelerate the formation of the foundation pit edge support, pour concrete, and add an appropriate amount of fast-setting additives; if it is in the concrete pouring stage, pour concrete and add an appropriate amount of fast-setting additives; Step 4: Retest on the third day. If there is no alarm after retest on the third day and A t ≤±3mm, the event is archived. If the alarm still occurs after retesting on the third day and A t ≥±3mm, the owner, general contractor, designer, construction participants, supervisor, and monitoring party will hold a meeting to decide on a solution and finally archive the incident; Accumulated data alarm: Based on the safety value limit value assigned by the design, comprehensive judgment is made: Step 1: Check whether the accumulated data of the previous three days is an alarm. If no alarm is given and A L ≤±0.4%H, it is within the safety limit, otherwise it will proceed to the next judgment; Step 2: If the single rate alarm is not triggered and A t ≤±3mm, the safety value limit value assigned by the design is considered to be small. When the cumulative data alarm value exceeds 1.5 times the design cumulative alarm value, the owner, general contractor, designer, construction participant, supervisor, and monitoring party shall be organized to hold a meeting to make a decision. Otherwise, proceed to the next judgment; Step 3: Combine the situation of the adjacent inclination measurement to make a judgment. If the adjacent inclination measurement does not alarm and Aj≤±3mm, then combine the surrounding enclosure wall top displacement to see if an alarm is raised. If the enclosure wall top displacement also does not alarm and W≤3mm, the inclination measurement will enter the next day's monitoring. If the monitoring on the next day does not alarm and Aj≤±3mm, the surrounding enclosure wall top displacement will alarm. t ≤±3mm, the single-day rate alarm event ends and subsequent attention is strengthened; if the monitoring alarm is on the next day and A t ≥±3mm, the monitoring will be intensified on that day; if there is an alarm in the adjacent inclination measurement and A j ≥±3mm, perform the daily intensive monitoring; Step 4: Further judge whether the encrypted monitoring alarms. If the encrypted monitoring does not alarm on the day and A j ≤±3mm, the next day will be the next day. If there is no alarm during the next day, and A j ≤±3mm, the single-day rate alarm event ends. If the alarm still occurs when the test is repeated the next day and A t ≥±3mm, then proceed to the next step of in-depth judgment; if the day's intensive monitoring alarm and A t ≥±3mm, then proceed to the next step of in-depth judgment; Step 5: Conduct a comprehensive analysis of the actual working conditions of the foundation pit, considering four factors: whether there is a pile load on the edge of the foundation pit, whether the over-excavation / slope meets the requirements, whether the precipitation meets the requirements, and whether the support exposure time is too long; Step 6: Retest on the third day. If there is no alarm after retest on the third day and A t ≤±3mm, the event is archived. If the alarm still occurs after retesting on the third day and A t ≥±3mm, the owner, general contractor, designer, construction participants, supervisor, and monitoring party will hold a meeting to decide on a solution and finally archive the incident; The single-day inclinometer data is A t , the accumulated inclinometric data is A L , the adjacent inclinometric data is A j , the displacement of the top of the retaining wall is W, and the unit is mm.

2. The method according to claim 1, characterized in that Also includes: When there is no pile loading on the side of the foundation pit, the management personnel will be reminded to issue a warning prohibiting pile loading on the side of the foundation pit after inspecting the site. If there is pile loading on the side of the foundation pit, it is prohibited to pile soil or materials within 1 meter around the construction pit according to the specifications. To prevent landslides of the pit wall, abandoned soil shall not be piled within a certain distance on both sides of the pit top according to the soil conditions and the depth of the pit or trench. And according to the requirements of the specifications, it is judged whether the pile loading distance meets the requirements. If not, the pile loading will be handled immediately. If it is within the requirements of the specifications, it is recommended to remove or expand the pile loading distance.

3. The method according to claim 1, characterized in that Also includes: If there is no over-excavation or the slope does not meet the requirements, the management personnel will be reminded to pay attention to the potential hidden dangers caused by over-excavation; if there is over-excavation or the slope does not meet the requirements, proceed to the next step of judgment. If it is in the support formation stage, accelerate the steel bar binding and pour concrete to form angle braces; if it is only in the excavation stage, suspend construction.

4. The method according to claim 1, characterized in that Also includes: If H 水位 <H 开挖面 , the precipitation meets the requirements; otherwise, the precipitation well is started to carry out precipitation until the precipitation requirements are met.

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