Strength

Strength measures bodily power, athletic training, and the extent to which you can exert raw physical force.

A Strength check can model any attempt to lift, push, pull, or break something, to force your body through a space, or to otherwise apply brute force to a situation. The Athletics skill reflects aptitude in certain kinds of Strength checks.

Athletics. Your Strength (Athletics) check covers difficult situations you encounter while climbing, jumping, or swimming. Examples include the following activities:

• You attempt to climb a sheer or slippery cliff, avoid hazards while scaling a wall, or cling to a surface while something is trying to knock you off.
• You try to jump an unusually long distance or pull off a stunt midjump.
• You struggle to swim or stay afloat in treacherous currents, storm-tossed waves, or areas of thick seaweed. Or another creature tries to push or pull you underwater or otherwise interfere with your swimming.

Other Strength Checks. The GM might also call for a Strength check when you try to accomplish tasks like the following:

• Force open a stuck, locked, or barred door
• Break free of bonds
• Push through a tunnel that is too small
• Hang on to a wagon while being dragged behind it
• Tip over a statue
• Keep a boulder from rolling

You add your Strength modifier to your attack roll and your damage roll when attacking with a melee weapon such as a mace, a battleaxe, or a javelin. You use melee weapons to make melee attacks in hand-to-hand combat, and some of them can be thrown to make a ranged attack.

Your Strength score determines the amount of weight you can bear. The following terms define what you can lift or carry.

Carrying Capacity. Your carrying capacity is your Strength score multiplied by 15. This is the weight (in pounds) that you can carry, which is high enough that most characters don't usually have to worry about it.

Push, Drag, or Lift. You can push, drag, or lift a weight in pounds up to twice your carrying capacity (or 30 times your Strength score). While pushing or dragging weight in excess of your carrying capacity, your speed drops to 5 feet.

Size and Strength. Larger creatures can bear more weight, whereas Tiny creatures can carry less. For each size category above Medium, double the creature's carrying capacity and the amount it can push, drag, or lift. For a Tiny creature, halve these weights.

The rules for lifting and carrying are intentionally simple. Here is a variant if you are looking for more detailed rules for determining how a character is hindered by the weight of equipment. When you use this variant, ignore the Strength column of the Armor table.

If you carry weight in excess of 5 times your Strength score, you are encumbered, which means your speed drops by 10 feet.

If you carry weight in excess of 10 times your Strength score, up to your maximum carrying capacity, you are instead heavily encumbered, which means your speed drops by 20 feet and you have disadvantage on ability checks, attack rolls, and saving throws that use Strength, Dexterity, or Constitution.
Source: SRD 2014, https://www.dndbeyond.com/sources/dnd/free-rules/rules-glossary#CarryingCapacityTable

When stymied by a locked door, iron gate, or even a blank stone wall, adventurers often resort to the most straightforward solution: breaking down the obstacle.

When time is of the essence, a character can make a Strength check to bash open a door, lift a portcullis, or otherwise force their way past a physical obstacle. When a single shoulder bash or a kick can’t open a door, but delay is impossible, a character might try to destroy the door with an axe, hammer, or similar weapon. Most doors in the dungeon are designed to withstand such punishment. They’re an inch or more thick and typically have 27 (5d10) hit points or more. The DC to bash down a door, or the AC to damage it, are as follows:

Some dungeon doors are especially thick, protected by magical wards, or reinforced with iron bars. These fortified doors have damage thresholds equal to their AC values. Thus, an attack that would deal less than 15 damage has no effect on a fortified wooden door. The DC to force open a fortified door is increased by 4 (so a fortified adamantine door can be bashed open with a Strength check of 27).

Given enough time, characters can dismantle most doors—unless even rolling a 20 on a Strength check can’t bash it open and even a critical hit can’t overcome its damage threshold.

In dire circumstances, characters might try to dig a tunnel or break through a wall.

Without a burrowing speed or magical assistance, a humanoid with the appropriate digging or tunneling tools can dig for up to 8 hours in a day. Over 8 hours, the creature can excavate a number of cubic feet of dirt equal to 10 + their Strength modifier. A creature can dig for additional hours using the Forced March rules, excavating an additional cubic foot per hour. Tunneling speed is halved if the digger needs to shore up walls to prevent collapse.

Soft stone, like the limestone walls of many caverns, can be excavated at one-quarter the speed of earth and doesn’t require shoring up.

A wall made of hard stone, like granite, simply can’t be broken in a short time frame without specialized equipment, immense strength, or magical assistance.
Source: Level Up Dungeon Delver’s Guide